After all the FPU state cleanups and finally finding the problem that
caused all our FPU save/restore problems, this re-introduces the
preloading of FPU state that was removed in commit b3b0870ef3ff ("i387:
do not preload FPU state at task switch time").
However, instead of simply reverting the removal, this reimplements
preloading with several fixes, most notably
- properly abstracted as a true FPU state switch, rather than as
open-coded save and restore with various hacks.
In particular, implementing it as a proper FPU state switch allows us
to optimize the CR0.TS flag accesses: there is no reason to set the
TS bit only to then almost immediately clear it again. CR0 accesses
are quite slow and expensive, don't flip the bit back and forth for
no good reason.
- Make sure that the same model works for both x86-32 and x86-64, so
that there are no gratuitous differences between the two due to the
way they save and restore segment state differently due to
architectural differences that really don't matter to the FPU state.
- Avoid exposing the "preload" state to the context switch routines,
and in particular allow the concept of lazy state restore: if nothing
else has used the FPU in the meantime, and the process is still on
the same CPU, we can avoid restoring state from memory entirely, just
re-expose the state that is still in the FPU unit.
That optimized lazy restore isn't actually implemented here, but the
infrastructure is set up for it. Of course, older CPU's that use
'fnsave' to save the state cannot take advantage of this, since the
state saving also trashes the state.
In other words, there is now an actual _design_ to the FPU state saving,
rather than just random historical baggage. Hopefully it's easier to
follow as a result.
This moves the bit that indicates whether a thread has ownership of the
FPU from the TS_USEDFPU bit in thread_info->status to a word of its own
(called 'has_fpu') in task_struct->thread.has_fpu.
This fixes two independent bugs at the same time:
- changing 'thread_info->status' from the scheduler causes nasty
problems for the other users of that variable, since it is defined to
be thread-synchronous (that's what the "TS_" part of the naming was
supposed to indicate).
So perfectly valid code could (and did) do
ti->status |= TS_RESTORE_SIGMASK;
and the compiler was free to do that as separate load, or and store
instructions. Which can cause problems with preemption, since a task
switch could happen in between, and change the TS_USEDFPU bit. The
change to TS_USEDFPU would be overwritten by the final store.
In practice, this seldom happened, though, because the 'status' field
was seldom used more than once, so gcc would generally tend to
generate code that used a read-modify-write instruction and thus
happened to avoid this problem - RMW instructions are naturally low
fat and preemption-safe.
- On x86-32, the current_thread_info() pointer would, during interrupts
and softirqs, point to a *copy* of the real thread_info, because
x86-32 uses %esp to calculate the thread_info address, and thus the
separate irq (and softirq) stacks would cause these kinds of odd
thread_info copy aliases.
This is normally not a problem, since interrupts aren't supposed to
look at thread information anyway (what thread is running at
interrupt time really isn't very well-defined), but it confused the
heck out of irq_fpu_usable() and the code that tried to squirrel
away the FPU state.
(It also caused untold confusion for us poor kernel developers).
It also turns out that using 'task_struct' is actually much more natural
for most of the call sites that care about the FPU state, since they
tend to work with the task struct for other reasons anyway (ie
scheduling). And the FPU data that we are going to save/restore is
found there too.
Thanks to Arjan Van De Ven <arjan@linux.intel.com> for pointing us to
the %esp issue.
Cc: Arjan van de Ven <arjan@linux.intel.com> Reported-and-tested-by: Raphael Prevost <raphael@buro.asia> Acked-and-tested-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception is
pending. In order to not leak FIP state from one process to another, we
need to do a floating point load after the fxsave of the old process,
and before the fxrstor of the new FPU state. That resets the state to
the (uninteresting) kernel load, rather than some potentially sensitive
user information.
We used to do this directly after the FPU state save, but that is
actually very inconvenient, since it
(a) corrupts what is potentially perfectly good FPU state that we might
want to lazy avoid restoring later and
(b) on x86-64 it resulted in a very annoying ordering constraint, where
"__unlazy_fpu()" in the task switch needs to be delayed until after
the DS segment has been reloaded just to get the new DS value.
Coupling it to the fxrstor instead of the fxsave automatically avoids
both of these issues, and also ensures that we only do it when actually
necessary (the FP state after a save may never actually get used). It's
simply a much more natural place for the leaked state cleanup.
Yes, taking the trap to re-load the FPU/MMX state is expensive, but so
is spending several days looking for a bug in the state save/restore
code. And the preload code has some rather subtle interactions with
both paravirtualization support and segment state restore, so it's not
nearly as simple as it should be.
Also, now that we no longer necessarily depend on a single bit (ie
TS_USEDFPU) for keeping track of the state of the FPU, we migth be able
to do better. If we are really switching between two processes that
keep touching the FP state, save/restore is inevitable, but in the case
of having one process that does most of the FPU usage, we may actually
be able to do much better than the preloading.
In particular, we may be able to keep track of which CPU the process ran
on last, and also per CPU keep track of which process' FP state that CPU
has. For modern CPU's that don't destroy the FPU contents on save time,
that would allow us to do a lazy restore by just re-enabling the
existing FPU state - with no restore cost at all!
This creates three helper functions that do the TS_USEDFPU accesses, and
makes everybody that used to do it by hand use those helpers instead.
In addition, there's a couple of helper functions for the "change both
CR0.TS and TS_USEDFPU at the same time" case, and the places that do
that together have been changed to use those. That means that we have
fewer random places that open-code this situation.
The intent is partly to clarify the code without actually changing any
semantics yet (since we clearly still have some hard to reproduce bug in
this area), but also to make it much easier to use another approach
entirely to caching the CR0.TS bit for software accesses.
Right now we use a bit in the thread-info 'status' variable (this patch
does not change that), but we might want to make it a full field of its
own or even make it a per-cpu variable.
Touching TS_USEDFPU without touching CR0.TS is confusing, so don't do
it. By moving it into the callers, we always do the TS_USEDFPU next to
the CR0.TS accesses in the source code, and it's much easier to see how
the two go hand in hand.
Commit 5b1cbac37798 ("i387: make irq_fpu_usable() tests more robust")
added a sanity check to the #NM handler to verify that we never cause
the "Device Not Available" exception in kernel mode.
However, that check actually pinpointed a (fundamental) race where we do
cause that exception as part of the signal stack FPU state save/restore
code.
Because we use the floating point instructions themselves to save and
restore state directly from user mode, we cannot do that atomically with
testing the TS_USEDFPU bit: the user mode access itself may cause a page
fault, which causes a task switch, which saves and restores the FP/MMX
state from the kernel buffers.
This kind of "recursive" FP state save is fine per se, but it means that
when the signal stack save/restore gets restarted, it will now take the
'#NM' exception we originally tried to avoid. With preemption this can
happen even without the page fault - but because of the user access, we
cannot just disable preemption around the save/restore instruction.
There are various ways to solve this, including using the
"enable/disable_page_fault()" helpers to not allow page faults at all
during the sequence, and fall back to copying things by hand without the
use of the native FP state save/restore instructions.
However, the simplest thing to do is to just allow the #NM from kernel
space, but fix the race in setting and clearing CR0.TS that this all
exposed: the TS bit changes and the TS_USEDFPU bit absolutely have to be
atomic wrt scheduling, so while the actual state save/restore can be
interrupted and restarted, the act of actually clearing/setting CR0.TS
and the TS_USEDFPU bit together must not.
Instead of just adding random "preempt_disable/enable()" calls to what
is already excessively ugly code, this introduces some helper functions
that mostly mirror the "kernel_fpu_begin/end()" functionality, just for
the user state instead.
Those helper functions should probably eventually replace the other
ad-hoc CR0.TS and TS_USEDFPU tests too, but I'll need to think about it
some more: the task switching functionality in particular needs to
expose the difference between the 'prev' and 'next' threads, while the
new helper functions intentionally were written to only work with
'current'.
The check for save_init_fpu() (introduced in commit 5b1cbac37798: "i387:
make irq_fpu_usable() tests more robust") was the wrong way around, but
I hadn't noticed, because my "tests" were bogus: the FPU exceptions are
disabled by default, so even doing a divide by zero never actually
triggers this code at all unless you do extra work to enable them.
So if anybody did enable them, they'd get one spurious warning.
Some code - especially the crypto layer - wants to use the x86
FP/MMX/AVX register set in what may be interrupt (typically softirq)
context.
That *can* be ok, but the tests for when it was ok were somewhat
suspect. We cannot touch the thread-specific status bits either, so
we'd better check that we're not going to try to save FP state or
anything like that.
Now, it may be that the TS bit is always cleared *before* we set the
USEDFPU bit (and only set when we had already cleared the USEDFP
before), so the TS bit test may actually have been sufficient, but it
certainly was not obviously so.
So this explicitly verifies that we will not touch the TS_USEDFPU bit,
and adds a few related sanity-checks. Because it seems that somehow
AES-NI is corrupting user FP state. The cause is not clear, and this
patch doesn't fix it, but while debugging it I really wanted the code to
be more obviously correct and robust.
Use standard ror64() instead of hand-written.
There is no standard ror64, so create it.
The difference is shift value being "unsigned int" instead of uint64_t
(for which there is no reason). gcc starts to emit native ROR instructions
which it doesn't do for some reason currently. This should make the code
faster.
Patch survives in-tree crypto test and ping flood with hmac(sha512) on.
Sometimes a software reset is needed. Then some registers are saved and
restored but the interrupt mask register is missing. It causes issues
with sdio devices whose interrupts are masked after reset.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Chris Ball <cjb@laptop.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since 3.2 kernel, the driver starts trying to assign the multi-io DACs
before the speaker, thus it assigns DAC2/3 for multi-io and DAC4 for
the speaker for a standard laptop setup like a HP, a speaker, a mic-in
and a line-in. However, on Acer Aspire 6935, it seems that the
speaker pin 0x14 must be connected with either DAC1 or 2; otherwise it
results in silence by some reason, although the codec itself allows
the routing to DAC3/4.
As a workaround, the connection list of each pin is reduced to be
mapped to either only DAC1/2 or DAC3/4, so that the compatible
assignment as in kernel 3.1 is achieved.
VT1705 codec has two ADCs where the secondary ADC has no MUX but only
a fixed connection to the mic pin. This confused the driver and it
tries always overriding the input-source selection by assumption of
the existing MUX for the secondary ADC, resulted in resetting the
input-source at each time PM (including power-saving) occurs.
The fix is simply to check the existence of MUX for secondary ADCs in
the initialization code.
BugLink: https://bugs.launchpad.net/bugs/930842
The reporter states that audio is inaudible by default without muting
'External Amplifier'. Add a quirk to handle his SSID so that changing
the control is not necessary.
Reported-and-tested-by: Benjamin Carlson <elderbubba0810@gmail.com> Signed-off-by: Daniel T Chen <crimsun@ubuntu.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While 7a401a972df8e18 ("backing-dev: ensure wakeup_timer is deleted")
addressed the problem of the bdi being freed with a queued wakeup
timer, there are other races that could happen if the wakeup timer
expires after/during bdi_unregister(), before bdi_destroy() is called.
wakeup_timer_fn() could attempt to wakeup a task which has already has
been freed, or could access a NULL bdi->dev via the wake_forker_thread
tracepoint.
Unfortunately in reducing W from 80 to 16 we ended up unrolling
the loop twice. As gcc has issues dealing with 64-bit ops on
i386 this means that we end up using even more stack space (>1K).
This patch solves the W reduction by moving LOAD_OP/BLEND_OP
into the loop itself, thus avoiding the need to duplicate it.
While the stack space still isn't great (>0.5K) it is at least
in the same ball park as the amount of stack used for our C sha1
implementation.
Note that this patch basically reverts to the original code so
the diff looks bigger than it really is.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The previous patch used the modulus operator over a power of 2
unnecessarily which may produce suboptimal binary code. This
patch changes changes them to binary ands instead.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
standard_receive3 will check the validity of the response from the
server (via checkSMB). It'll pass the result of that check to handle_mid
which will dequeue it and mark it with a status of
MID_RESPONSE_MALFORMED if checkSMB returned an error. At that point,
standard_receive3 will also return an error, which will make the
demultiplex thread skip doing the callback for the mid.
This is wrong -- if we were able to identify the request and the
response is marked malformed, then we want the demultiplex thread to do
the callback. Fix this by making standard_receive3 return 0 in this
situation.
Reported-and-Tested-by: Mark Moseley <moseleymark@gmail.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, it's always set to 0 (no oplock requested).
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order to enable temperature mode aka automatic mode for the F75373 and
F75375 chips, the two FANx_MODE bits in the fan configuration register
need be set to 01, not 10.
When a SD card is hot removed without umount, del_gendisk() will call
bdi_unregister() without destroying/freeing it. This leaves the bdi in
the bdi->dev = NULL, bdi->wb.task = NULL, bdi->bdi_list removed state.
When sync(2) gets the bdi before bdi_unregister() and calls
bdi_queue_work() after the unregister, trace_writeback_queue will be
dereferencing the NULL bdi->dev. Fix it with a simple test for NULL.
bdi_prune_sb() resets sb->s_bdi to default_backing_dev_info when the
tearing down the original bdi. Fix trace_writeback_single_inode to
use sb->s_bdi=default_backing_dev_info rather than bdi->dev=NULL for a
teared down bdi.
Reported-by: Rabin Vincent <rabin@rab.in> Tested-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current code checks for stored_mpdu_num > 1, causing
the reorder_timer to be triggered indefinitely, but the
frame is never timed-out (until the next packet is received)
Signed-off-by: Eliad Peller <eliad@wizery.com> Acked-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
8<----------------------------------------------------------------------
From: Ralf Roesch <ralf.roesch@rw-gmbh.de>
Date: Wed, 16 Nov 2011 09:33:50 +0100
Subject: net: enable TC35815 for MIPS again
TX493[8,9] MIPS SoCs support 2 Ethernet channels of type TC35815
which are connected to the internal PCI controller.
And JMR3927 MIPS board has a TC35815 chip on board.
These dependencies were lost on movement to drivers/net/ethernet/toshiba.
Signed-off-by: Ralf Roesch <ralf.roesch@rw-gmbh.de> Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit adb5066 "ath9k_hw: do not apply the 2.4 ghz ack timeout
workaround to cts" reduced the hardware CTS timeout to the normal
values specified by the standard, but it turns out while it doesn't
need the same extra time that it needs for the ACK timeout, it
does need more than the value specified in the standard, but only
for 2.4 GHz.
This patch brings the CTS timeout value in sync with the initialization
values, while still allowing adjustment for bigger distances.
Signed-off-by: Felix Fietkau <nbd@openwrt.org> Reported-by: Seth Forshee <seth.forshee@canonical.com> Reported-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b4a82a0 "ath9k_hw: fix interpretation of the rx KeyMiss flag"
fixed the interpretation of the KeyMiss flag for keycache based lookups,
however WEP encryption uses a static index, so KeyMiss is always asserted
for it, even though frames are decrypted properly.
Fix this by clearing the ATH9K_RXERR_KEYMISS flag if no keycache based
lookup was performed.
Signed-off-by: Felix Fietkau <nbd@openwrt.org> Reported-by: Laurent Bonnans <bonnans.l@gmail.com> Reported-by: Jurica Vukadin <u.ra604@googlemail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
all works need to be initialized before ieee80211_register_hw
to prevent mac80211 call backs such as drv_start, drv_config
getting started. otherwise we would queue/cancel works before
initializing them and it leads to kernel panic.
this issue can be recreated with the following script
in Chrome laptops with AR928X cards, with background scan
running (or) Network manager is running
while true
do
sudo modprobe -v ath9k
sleep 3
sudo modprobe -r ath9k
sleep 3
done
Cc: Gary Morain <gmorain@google.com> Cc: Paul Stewart <pstew@google.com> Cc: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com> Tested-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com> Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com> Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44263 Acked-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is never correct to use intel_crtc->bpp in intel_dp_link_required,
so instead pass an explicit bpp in to this function. This patch
only supports 18bpp and 24bpp modes, which means that 10bpc modes will
be computed incorrectly. Fixing that will require more extensive
changes, and so must be addressed separately from this bugfix.
intel_dp_link_required is called from intel_dp_mode_valid and
intel_dp_mode_fixup.
* intel_dp_mode_valid is called to list supported modes; in this case,
the current crtc values cannot be relevant as the modes in question
may never be selected. Thus, using intel_crtc->bpp is never right.
* intel_dp_mode_fixup is called during mode setting, but it is run
well before ironlake_crtc_mode_set is called to set intel_crtc->bpp,
so using intel_crtc-bpp in this path can only ever get a stale
value.
Cc: Lubos Kolouch <lubos.kolouch@gmail.com> Cc: Adam Jackson <ajax@redhat.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=42263
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44881 Tested-by: Dave Airlie <airlied@redhat.com> Tested-by: camalot@picnicpark.org (Dell Latitude 6510) Tested-by: Roland Dreier <roland@digitalvampire.org> Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
By adding following objects:
bench/mem-memcpy-x86-64-asm.o
the x86_64 perf binary ended up with executable stack.
The reason was that above object are assembler sourced and is missing the
GNU-stack note section. In such case the linker assumes that the final binary
should not be restricted at all and mark the stack as RWX.
Adding section ".note.GNU-stack" definition to mentioned object, with all
flags disabled, thus omiting this object from linker stack flags decision.
A git bisect shows commit f3bda2c as the cause. However, looking back
through the git history, I saw commit 640c03c which seems to have
removed the required initialization for perf_sample->period. The problem
only started showing after commit f3bda2c. The below patch re-introduces
the initialization and it fixes the problem for me.
Recent addition of code to find already allocated VFs failed to take
account that systems with 2 or more multi-port SR-IOV capable controllers
might have already enabled VFs. Make sure that the VFs the function is
finding are actually subordinate to the particular instance of the adapter
that is looking for them and not subordinate to some device that has
previously enabled SR-IOV.
This is applicable to 3.2+ kernels.
Reported-by: David Ahern <daahern@cisco.com> Signed-off-by: Greg Rose <gregory.v.rose@intel.com> Tested-by: Robert E Garrett <robertX.e.garrett@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Recent addition of code to find already allocated VFs failed to take
account that systems with 2 or more multi-port SR-IOV capable controllers
might have already enabled VFs. Make sure that the VFs the function is
finding are actually subordinate to the particular instance of the adapter
that is looking for them and not subordinate to some device that has
previously enabled SR-IOV.
This bug exists in 3.2 stable as well as 3.3 release candidates.
Reported-by: David Ahern <daahern@cisco.com> Signed-off-by: Greg Rose <gregory.v.rose@intel.com> Tested-by: Robert E Garrett <robertX.e.garrett@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver uses the pstate number from the status register as index in
its table of ACPI pstates (powernow_table). This is wrong as this is
not a 1-to-1 mapping.
For example we can have _PSS information to just utilize Pstate 0 and
Pstate 4, ie.
In this example the driver's powernow_table has just 2 entries. Using
the pstate number (4) as index into this table is just plain wrong.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Due to CPB we can't directly map SW Pstates to Pstate MSRs. Get rid of
the paranoia check. (assuming that the ACPI Pstate information is
correct.)
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Axel Lin <axel.lin@gmail.com> Acked-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I discovered this deadlock condition awhile ago working on RAMster
but it affects zcache as well. The list spinlock must be
locked prior to the page spinlock and released after. As
a result, the page copy must also be done while the locks are held.
Applies to 3.2. Konrad, please push (via GregKH?)...
this is definitely a bug fix so need not be pushed during
a -rc0 window.
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SWIZ_BITS > 8 results in a much larger number of "tmem_obj"
allocations, likely one per page-placed-in-frontswap. The
tmem_obj is not huge (roughly 100 bytes), but it is large
enough to add a not-insignificant memory overhead to zcache.
The SWIZ_BITS=8 will get roughly the same lock contention
without the space wastage.
The effect of SWIZ_BITS can be thought of as "2^SWIZ_BITS is
the number of unique oids that be generated" (This concept is
limited to frontswap's use of tmem).
As ZTE have and will use more pid for new products this year,
so we need to add some new zte 3g-dongle's pid on option.c ,
and delete one pid 0x0154 because it use for mass-storage port.
Signed-off-by: Rui li <li.rui27@zte.com.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Netlogic XLP SoC's on-chip USB controller appears as a PCI
USB device, but does not need the EHCI/OHCI handoff done in
usb/host/pci-quirks.c.
The pci-quirks.c is enabled for all vendors and devices, and is
enabled if USB and PCI are configured.
If we do not skip the qurik handling on XLP, the readb() call in
ehci_bios_handoff() will cause a crash since byte access is not
supported for EHCI registers in XLP.
Signed-off-by: Jayachandran C <jayachandranc@netlogicmicro.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ab943a2e125b (USB: gadget: gadget zero uses new suspend/resume hooks)
introduced a copy-paste error where f_loopback.c writes to a variable
declared in f_sourcesink.c. This prevents one from creating gadgets
that only have a loopback function.
Signed-off-by: Timo Juhani Lindfors <timo.lindfors@iki.fi> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The usb/ch9.h will be installed to /usr/include/linux,
and be used from user space.
But le16_to_cpu() is only defined for kernel code.
Without this patch, user space compile will be broken.
Special thanks to Stefan Becker
Reported-by: Stefan Becker <chemobejk@gmail.com> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In https://bugs.archlinux.org/task/27996, failure of driver r8712u is
reported, with a timeout during module loading due to synchronous loading
of the firmware. The code now uses request_firmware_nowait().
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the image processing by special-casing val == 0.
I have tested this change on an Asus G50V laptop only.
Cc: Jakub Schmidtke <sjakub@gmail.com> Cc: Kevin A. Granade <kevin.granade@gmail.com> Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the PAGE CODE field is not set to zero when the EVPD bit is set
to zero, the command shall be terminated with CHECK CONDITION
status, with the sense key set to ILLEGAL REQUEST, and the
additional sense code set to INVALID FIELD IN CDB.
Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the device server does not implement the requested vital product
data page, then the command shall be terminated with CHECK CONDITION
status, with the sense key set to ILLEGAL REQUEST, and the
additional sense code set to INVALID FIELD IN CDB.
Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds a work-around for handling zero allocation length
control CDBs (type SCF_SCSI_CONTROL_SG_IO_CDB) that was causing an
OOPs with the following raw calls:
This patch will follow existing zero-length handling for data I/O
and silently return with GOOD status. This addresses the zero length
issue, but the proper long-term resolution for handling arbitary
allocation lengths will be to refactor out data-phase handling in
individual CDB emulation logic within target_core_cdb.c
Reported-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to SPC-4, the sense key for commands that are failed with
INVALID FIELD IN PARAMETER LIST and INVALID FIELD IN CDB should be
ILLEGAL REQUEST (5h) rather than ABORTED COMMAND (Bh). Without this
patch, a tcm_loop LUN incorrectly gives:
# sg_raw -r 1 -v /dev/sda 3 1 0 0 ff 0
Sense Information:
Fixed format, current; Sense key: Aborted Command
Additional sense: Invalid field in cdb
Raw sense data (in hex):
70 00 0b 00 00 00 00 0a 00 00 00 00 24 00 00 00
00 00
While a real SCSI disk gives:
Sense Information:
Fixed format, current; Sense key: Illegal Request
Additional sense: Invalid field in cdb
Raw sense data (in hex):
70 00 05 00 00 00 00 18 00 00 00 00 24 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
with the main point being that the real disk gives a sense key of
ILLEGAL REQUEST (5h).
Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Initiators that aren't the active reservation holder should be able to
do a PERSISTENT RESERVE IN command in all cases, so add it to the list
of allowed CDBs in core_scsi3_pr_seq_non_holder().
Signed-off-by: Marco Sanvido <marco@purestorage.com> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* d) Establish a unit attention condition for the
* initiator port associated with every I_T nexus
* that lost its registration other than the I_T
* nexus on which the PERSISTENT RESERVE OUT command
* was received, with the additional sense code set
* to REGISTRATIONS PREEMPTED.
and
* e) Establish a unit attention condition for the initiator
* port associated with every I_T nexus that lost its
* persistent reservation and/or registration, with the
* additional sense code set to REGISTRATIONS PREEMPTED;
but the actual code accidentally uses ASCQ_2AH_RESERVATIONS_PREEMPTED
instead of ASCQ_2AH_REGISTRATIONS_PREEMPTED. Fix this.
Signed-off-by: Marco Sanvido <marco@purestorage.com> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_SMP=n CONFIG_DEBUG_VM=y
CONFIG_DEBUG_SPINLOCK=n kernel: spin_is_locked() is then always false,
and so triggers some BUGs in Transparent HugePage codepaths.
asm-generic/bug.h mentions this problem, and provides a WARN_ON_SMP(x);
but being too lazy to add VM_BUG_ON_SMP, BUG_ON_SMP, WARN_ON_SMP_ONCE,
VM_WARN_ON_SMP_ONCE, just test NR_CPUS != 1 in the existing VM_BUG_ONs.
Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When isolating pages for migration, migration starts at the start of a
zone while the free scanner starts at the end of the zone. Migration
avoids entering a new zone by never going beyond the free scanned.
Unfortunately, in very rare cases nodes can overlap. When this happens,
migration isolates pages without the LRU lock held, corrupting lists
which will trigger errors in reclaim or during page free such as in the
following oops
The "X" in the taint flag means that external modules were loaded but but
is unrelated to the bug triggering. The real problem was because the PFN
layout looks like this
The fix is straight-forward. isolate_migratepages() has to make a
similar check to isolate_freepage to ensure that it never isolates pages
from a zone it does not hold the LRU lock for.
This was discovered in a 3.0-based kernel but it affects 3.1.x, 3.2.x
and current mainline.
Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Error handling in msm_iommu_unmap() is broken. On some error
conditions retval is set to a non-zero value which causes
the function to return 'len' at the end. This hides the
error from the user. Zero should be returned in those error
cases.
Cc: David Brown <davidb@codeaurora.org> Cc: Stepan Moskovchenko <stepanm@codeaurora.org> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Acked-by: David Brown <davidb@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On some systems the IVRS table does not contain all PCI
devices present in the system. In case a device not present
in the IVRS table is translated by the IOMMU no DMA is
possible from that device by default.
This patch fixes this by removing the DTE entry for every
PCI device present in the system and not covered by IVRS.
The driver accidentally exchanged the left/right fields for stereo AC'97
mixer registers. This affected only the aux and CD inputs because the
line input bypasses the AC'97 codec and the mic input is mono; cards
without AC'97 (Xonar DS/DG/HDAV Slim, HG2PCI, HiFier) were not affected.
Reported-and-tested-by: Abby Cedar <abbycedar@yahoo.com.au> Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This fixes a memory-corrupting bug: not only does it cause the warning,
but as a result of dropping the refcount to zero, it causes the
pcmcia_socket0 device structure to be freed while it still has
references, causing slab caches corruption. A fatal oops quickly
follows this warning - often even just a 'dmesg' following the warning
causes the kernel to oops.
While testing suspend/resume on an ARM device with PCMCIA support, and a
CF card inserted, I found that after five suspend and resumes, the
kernel would complain, and shortly die after with slab corruption.
WARNING: at include/linux/kref.h:41 kobject_get+0x28/0x50()
As the message doesn't give a clue about which kobject, and the built-in
debugging in drivers/base/power/main.c happens too late, this was added
right before each get_device():
+ /* now, add the new card */
+ pcmcia_bus_add(skt);
+ return 0;
+}
As can be seen, the original function called pcmcia_get_socket() and
pcmcia_put_socket() around the guts, whereas the replacement code
calls pcmcia_put_socket() only in one path. This creates an imbalance
in the refcounting.
Testing with pcmcia_put_socket() put removed shows that the bug is gone:
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Susan Gao <sgao@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch addresses a bug with sendtargets discovery where INADDR_ANY (0.0.0.0)
+ IN6ADDR_ANY_INIT ([0:0:0:0:0:0:0:0]) network portals where incorrectly being
reported back to initiators instead of the address of the connecting interface.
To address this, save local socket ->getname() output during iscsi login setup,
and makes iscsit_build_sendtargets_response() return these TargetAddress keys
when INADDR_ANY or IN6ADDR_ANY_INIT portals are in use.
Reported-by: Dax Kelson <dkelson@gurulabs.com> Reported-by: Andy Grover <agrover@redhat.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes a bug where the iscsit_add_reject_from_cmd() call
from a failure to iscsit_alloc_buffs() was incorrectly passing
add_to_conn=1 and causing a double list_add after iscsi_cmd->i_list
had already been added in iscsit_handle_scsi_cmd().
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch addresses a bug where iscsit_free_cmd() was incorrectly calling
iscsit_release_cmd() for ISCSI_OP_REJECT because iscsi_add_reject*() will
overwrite the original iscsi_cmd->iscsi_opcode assignment. This bug was
introduced with the following commit:
We do want to allow lock debugging for GPL-compatible modules
that are not (yet) built in-tree. This was disabled as a
side-effect of commit 2449b8ba0745327c5fa49a8d9acffe03b2eded69
('module,bug: Add TAINT_OOT_MODULE flag for modules not built
in-tree'). Lock debug warnings now include taint flags, so
kernel developers should still be able to deflect warnings
caused by out-of-tree modules.
The TAINT_PROPRIETARY_MODULE flag for non-GPL-compatible modules
will still disable lock debugging.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Nick Bowler <nbowler@elliptictech.com> Cc: Dave Jones <davej@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Debian kernel maintainers <debian-kernel@lists.debian.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alan Cox <alan@linux.intel.com> Link: http://lkml.kernel.org/r/1323268258.18450.11.camel@deadeye Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's unlikely that TAINT_FIRMWARE_WORKAROUND causes false
lockdep messages, so do not disable lockdep in that case.
We still want to keep lockdep disabled in the
TAINT_OOT_MODULE case:
- bin-only modules can cause various instabilities in
their and in unrelated kernel code
- they are impossible to debug for kernel developers
- they also typically do not have the copyright license
permission to link to the GPL-ed lockdep code.
Suggested-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-xopopjjens57r0i13qnyh2yo@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For null user mounts, do not invoke string length function
during session setup.
Reported-and-Tested-by: Chris Clayton <chris2553@googlemail.com> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
NCT6776F can select fan input pins for fans 3 to 5 with a secondary set of
chip register bits. Check that second set of bits in addition to the first set
to detect if fans 3..5 are monitored.
ecryptfs_write() can enter an infinite loop when truncating a file to a
size larger than 4G. This only happens on architectures where size_t is
represented by 32 bits.
This was caused by a size_t overflow due to it incorrectly being used to
store the result of a calculation which uses potentially large values of
type loff_t.
[tyhicks@canonical.com: rewrite subject and commit message] Signed-off-by: Li Wang <liwang@nudt.edu.cn> Signed-off-by: Yunchuan Wen <wenyunchuan@kylinos.com.cn> Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The problem this patch solves is that the forcewake accounting
necessary for register reads is protected by dev->struct_mutex. But the
hangcheck and error_capture code need to access registers without
grabbing this mutex because we hold it while waiting for the gpu.
So a new lock is required. Because currently the error_state capture
is called from the error irq handler and the hangcheck code runs from
a timer, it needs to be an irqsafe spinlock (note that the registers
used by the irq handler (neglecting the error handling part) only uses
registers that don't need the forcewake dance).
We could tune this down to a normal spinlock when we rework the
error_state capture and hangcheck code to run from a workqueue. But
we don't have any read in a fastpath that needs forcewake, so I've
decided to not care much about overhead.
This prevents tests/gem_hangcheck_forcewake from i-g-t from killing my
snb on recent kernels - something must have slightly changed the
timings. On previous kernels it only trigger a WARN about the broken
locking.
v2: Drop the previous patch for the register writes.
v3: Improve the commit message per Chris Wilson's suggestions.
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com> Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
TV Out refresh rate was half of the specification for almost all modes.
Due to this reason pixel clock was so low for some modes causing flickering screen.
Otherwise hangcheck spuriously fires when running blitter/bsd-only
workloads.
Contrary to a similar patch by Ben Widawsky this does not check
INSTDONE of the other rings. Chris Wilson implied that in a failure to
detect a hang, most likely because INSTDONE was fluctuating. Thus only
check ACTHD, which as far as I know is rather reliable. Also, blitter
and bsd rings can't launch complex tasks from a single instruction
(like 3D_PRIM on the render with complex or even infinite shaders).
This fixes spurious gpu hang detection when running
tests/gem_hangcheck_forcewake on snb/ivb.
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On DP monitor hot remove, clear DP_AUDIO_OUTPUT_ENABLE accordingly,
so that the audio driver will receive hot plug events and take action
to refresh its device state and ELD contents.
Note that the DP_AUDIO_OUTPUT_ENABLE bit may be enabled or disabled
only when the link training is complete and set to "Normal".
Tested OK for both hot plug/remove and DPMS on/off.
On HDMI monitor hot remove, clear SDVO_AUDIO_ENABLE accordingly, so that
the audio driver will receive hot plug events and take action to refresh
its device state and ELD contents.
The cleared SDVO_AUDIO_ENABLE bit needs to be restored to prevent losing
HDMI audio after DPMS on.
CC: Wang Zhenyu <zhenyu.z.wang@intel.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we hit EIO while writing LVID, the buffer uptodate bit is cleared.
This then results in an anoying warning from mark_buffer_dirty() when we
write the buffer again. So just set uptodate flag unconditionally.
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the SNAPSHOT_CREATE_IMAGE ioctl, if the call to hibernation_snapshot()
fails, the frozen tasks are not thawed.
And in the case of success, if we happen to exit due to a successful freezer
test, all tasks (including those of userspace) are thawed, whereas actually
we should have thawed only the kernel threads at that point. Fix both these
issues.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 2aede851ddf08666f68ffc17be446420e9d2a056 (PM / Hibernate: Freeze
kernel threads after preallocating memory) moved the freezing of kernel
threads to hibernation_snapshot() function.
So now, if the call to hibernation_snapshot() returns early due to a
successful hibernation test, the caller has to thaw processes to ensure
that the system gets back to its original state.
But in SNAPSHOT_CREATE_IMAGE hibernation ioctl, the caller does not thaw
processes in case hibernation_snapshot() returned due to a successful
freezer test. Fix this issue. But note we still send the value of 'in_suspend'
(which is now 0) to userspace, because we are not in an error path per-se,
and moreover, the value of in_suspend correctly depicts the situation here.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This issue happens under the following conditions:
1. preemption is off
2. __ARCH_WANT_INTERRUPTS_ON_CTXSW is defined
3. RT scheduling class
4. SMP system
Sequence is as follows:
1.suppose current task is A. start schedule()
2.task A is enqueued pushable task at the entry of schedule()
__schedule
prev = rq->curr;
...
put_prev_task
put_prev_task_rt
enqueue_pushable_task
4.pick the task B as next task.
next = pick_next_task(rq);
3.rq->curr set to task B and context_switch is started.
rq->curr = next;
4.At the entry of context_swtich, release this cpu's rq->lock.
context_switch
prepare_task_switch
prepare_lock_switch
raw_spin_unlock_irq(&rq->lock);
5.Shortly after rq->lock is released, interrupt is occurred and start IRQ context
6.try_to_wake_up() which called by ISR acquires rq->lock
try_to_wake_up
ttwu_remote
rq = __task_rq_lock(p)
ttwu_do_wakeup(rq, p, wake_flags);
task_woken_rt
7.push_rt_task picks the task A which is enqueued before.
task_woken_rt
push_rt_tasks(rq)
next_task = pick_next_pushable_task(rq)
8.At find_lock_lowest_rq(), If double_lock_balance() returns 0,
lowest_rq can be the remote rq.
(But,If preemption is on, double_lock_balance always return 1 and it
does't happen.)
push_rt_task
find_lock_lowest_rq
if (double_lock_balance(rq, lowest_rq))..
9.find_lock_lowest_rq return the available rq. task A is migrated to
the remote cpu/rq.
push_rt_task
...
deactivate_task(rq, next_task, 0);
set_task_cpu(next_task, lowest_rq->cpu);
activate_task(lowest_rq, next_task, 0);
10. But, task A is on irq context at this cpu.
So, task A is scheduled by two cpus at the same time until restore from IRQ.
Task A's stack is corrupted.
To fix it, don't migrate an RT task if it's still running.
Polling the outputs when the device is suspended can result in erroneous
status updates. Disable output polling during suspend to prevent this
from happening.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Due to a race it was possible for a fence to be destroyed while another
thread was trying to synchronise with it. If this happened in the fallback
non-semaphore path, it lead to the following oops due to fence->channel
being NULL.
The value of this register is transferred to the V_COUNTER register at the
beginning of vertical blank. V_COUNTER is the reference for VLINE waits and
goes from VIEWPORT_Y_START to VIEWPORT_Y_START+VIEWPORT_HEIGHT during scanout,
so if VIEWPORT_Y_START is not 0, V_COUNTER actually went backwards at the
beginning of vertical blank, and VLINE waits excluding the whole scanout area
could never finish (possibly only if VIEWPORT_Y_START is larger than the length
of vertical blank in scanlines). Setting DESKTOP_HEIGHT to the framebuffer
height should prevent this for any kind of VLINE wait.
Looks like change "PM QoS: Move and rename the implementation files"
merged during the 3.2 development cycle made PM QoS depend on
CONFIG_PM which depends on (PM_SLEEP || PM_RUNTIME).
That breaks CPU C-states with kernels not having these CONFIGs, causing CPUs
to spend time in Polling loop idle instead of going into deep C-states,
consuming way way more power. This is with either acpi idle or intel idle
enabled.
Either CONFIG_PM should be enabled with any pm_qos users or
the !CONFIG_PM pm_qos_request() should return sane defaults not to break
the existing users. Here's is the patch for the latter option.
[rjw: Modified the changelog slightly.]
Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>