Joerg Roedel [Fri, 9 Oct 2009 14:08:32 +0000 (16:08 +0200)]
KVM: SVM: Add tracepoint for skinit instruction
This patch adds a tracepoint for the event that the guest
executed the SKINIT instruction. This information is
important because SKINIT is an SVM extenstion not yet
implemented by nested SVM and we may need this information
for debugging hypervisors that do not yet run on nested SVM.
Joerg Roedel [Fri, 9 Oct 2009 14:08:26 +0000 (16:08 +0200)]
KVM: SVM: Move INTR vmexit out of atomic code
The nested SVM code emulates a #vmexit caused by a request
to open the irq window right in the request function. This
is a bug because the request function runs with preemption
and interrupts disabled but the #vmexit emulation might
sleep. This can cause a schedule()-while-atomic bug and is
fixed with this patch.
Glauber Costa [Tue, 6 Oct 2009 17:24:50 +0000 (13:24 -0400)]
KVM: x86: include pvclock MSRs in msrs_to_save
For a while now, we are issuing a rdmsr instruction to find out which
msrs in our save list are really supported by the underlying machine.
However, it fails to account for kvm-specific msrs, such as the pvclock
ones.
This patch moves then to the beginning of the list, and skip testing them.
Cc: stable@kernel.org Signed-off-by: Glauber Costa <glommer@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Jan Kiszka [Mon, 5 Oct 2009 11:07:21 +0000 (13:07 +0200)]
KVM: x86: Rework guest single-step flag injection and filtering
Push TF and RF injection and filtering on guest single-stepping into the
vender get/set_rflags callbacks. This makes the whole mechanism more
robust wrt user space IOCTL order and instruction emulations.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Jan Kiszka [Fri, 2 Oct 2009 22:31:21 +0000 (00:31 +0200)]
KVM: x86: Refactor guest debug IOCTL handling
Much of so far vendor-specific code for setting up guest debug can
actually be handled by the generic code. This also fixes a minor deficit
in the SVM part /wrt processing KVM_GUESTDBG_ENABLE.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
KVM: Kill the confusing tsc_ref_khz and ref_freq variables
They are globals, not clearly protected by any ordering or locking, and
vulnerable to various startup races.
Instead, for variable TSC machines, register the cpufreq notifier and get
the TSC frequency directly from the cpufreq machinery. Not only is it
always right, it is also perfectly accurate, as no error prone measurement
is required.
On such machines, when a new CPU online is brought online, it isn't clear what
frequency it will start with, and it may not correspond to the reference, thus
in hardware_enable we clear the cpu_tsc_khz variable to zero and make sure
it is set before running on a VCPU.
This patch reorganizes the logic in svm_interrupt_allowed to
make it better to read. This is important because the logic
is a lot more complicated with Nested SVM.
Alexander Graf [Tue, 15 Sep 2009 09:37:46 +0000 (11:37 +0200)]
KVM: Activate Virtualization On Demand
X86 CPUs need to have some magic happening to enable the virtualization
extensions on them. This magic can result in unpleasant results for
users, like blocking other VMMs from working (vmx) or using invalid TLB
entries (svm).
Currently KVM activates virtualization when the respective kernel module
is loaded. This blocks us from autoloading KVM modules without breaking
other VMMs.
To circumvent this problem at least a bit, this patch introduces on
demand activation of virtualization. This means, that instead
virtualization is enabled on creation of the first virtual machine
and disabled on destruction of the last one.
So using this, KVM can be easily autoloaded, while keeping other
hypervisors usable.
Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Mohammed Gamal [Tue, 1 Sep 2009 10:48:18 +0000 (12:48 +0200)]
KVM: VMX: Enhance invalid guest state emulation
- Change returned handle_invalid_guest_state() to return relevant exit codes
- Move triggering the emulation from vmx_vcpu_run() to vmx_handle_exit()
- Return to userspace instead of repeatedly trying to emulate instructions that have already failed
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Gleb Natapov [Mon, 24 Aug 2009 08:54:26 +0000 (11:54 +0300)]
KVM: Drop kvm->irq_lock lock from irq injection path
The only thing it protects now is interrupt injection into lapic and
this can work lockless. Even now with kvm->irq_lock in place access
to lapic is not entirely serialized since vcpu access doesn't take
kvm->irq_lock.
Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Julia Lawall [Sun, 9 Aug 2009 09:42:32 +0000 (11:42 +0200)]
VIDEO: Correct use of request_region/request_mem_region
request_region should be used with release_region, not request_mem_region.
Geert Uytterhoeven pointed out that in the case of drivers/video/gbefb.c,
the problem is actually the other way around; request_mem_region should be
used instead of request_region.
The semantic patch that finds/fixes this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@r1@
expression start;
@@
request_region(start,...)
@b1@
expression r1.start;
@@
request_mem_region(start,...)
@depends on !b1@
expression r1.start;
expression E;
@@
Helge Deller [Wed, 2 Dec 2009 23:29:15 +0000 (00:29 +0100)]
modules: don't export section names of empty sections via sysfs
On the parisc architecture we face for each and every loaded kernel module
this kernel "badness warning":
sysfs: cannot create duplicate filename '/module/ac97_bus/sections/.text'
Badness at fs/sysfs/dir.c:487
Reason for that is, that on parisc all kernel modules do have multiple
.text sections due to the usage of the -ffunction-sections compiler flag
which is needed to reach all jump targets on this platform.
An objdump on such a kernel module gives:
Sections:
Idx Name Size VMA LMA File off Algn
0 .note.gnu.build-id 00000024000000000000000000000034 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
1 .text 00000000000000000000000000000058 2**0
CONTENTS, ALLOC, LOAD, READONLY, CODE
2 .text.ac97_bus_match 0000001c000000000000000000000058 2**2
CONTENTS, ALLOC, LOAD, READONLY, CODE
3 .text 000000000000000000000000000000d4 2**0
CONTENTS, ALLOC, LOAD, READONLY, CODE
...
Since the .text sections are empty (size of 0 bytes) and won't be
loaded by the kernel module loader anyway, I don't see a reason
why such sections need to be listed under
/sys/module/<module_name>/sections/<section_name> either.
The attached patch does solve this issue by not exporting section
names which are empty.
This fixes bugzilla http://bugzilla.kernel.org/show_bug.cgi?id=14703
Daniel Mack [Tue, 1 Dec 2009 17:17:18 +0000 (18:17 +0100)]
[ARM] pxamci: call mmc_remove_host() before freeing resources
mmc_remove_host() will cause the mmc core to switch off the bus power by
eventually calling pxamci_set_ios(). This function uses the regulator or
the GPIO which have been freed already.
Johannes Weiner [Tue, 1 Dec 2009 21:17:48 +0000 (13:17 -0800)]
rtc-x1205: fix rtc_time to y2k register value conversion
The possible CCR_Y2K register values are 19 or 20 and struct rtc_time's
tm_year is in years since 1900.
The function translating rtc_time to register values assumes tm_year to be
years since first christmas, though, and we end up storing 0 or 1 in the
CCR_Y2K register, which the hardware does not refuse to do.
A subsequent probing of the clock fails due to the invalid value range in
the register, though.
[ And if it didn't, reading the clock would yield a bogus year because
the function translating registers to tm_year is assuming a register
value of 19 or 20. ]
This fixes the conversion from years since 1900 in tm_year to the
corresponding CCR_Y2K value of 19 or 20.
Signed-off-by: Johannes Weiner <jw@emlix.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Paul Gortmaker <p_gortmaker@yahoo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sam Ravnborg [Tue, 1 Dec 2009 21:17:44 +0000 (13:17 -0800)]
kbuild: stepping down as maintainer
It has been fun but the last year or more it has been a duty and a burden.
So I leave it open for others to take over.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Anibal Monsalve Salazar <anibal@debian.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Following issues have been addressed on DA8XX/OMAP-L1XX:
a. Screen misalignment during booting when frame buffer console is
enabled.
b. Driver was configured always in PSEUDOCOLOR mode. This patch
dynamically configures the driver either in PSEUDOCOLOUR or TRUECOLOR
mode depending on bpp.
c. The RED and BLUE offsets were interchanged resulting in wrong
bootup logo colour.
This patch has been tested on DA830/OMAP-L137 and DA850/OMAP-L138 EVMs.
Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com> Cc: Steve Chen <schen@mvista.com> Cc: Pavel Kiryukhin <pkiryukhin@ru.mvista.com> Cc: Krzysztof Helt <krzysztof.h1@wp.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
USB: Add support for Mobilcom Debitel USB UMTS Surf-Stick to option driver
USB: work around for EHCI with quirky periodic schedules
USB: musb: Fix CPPI IRQs not being signaled
USB: musb: respect usb_request->zero in control requests
USB: musb: fix ISOC Tx programming for CPPI DMAs
USB: musb: Remove unwanted message in boot log
usb: amd5536udc: fixed shared interrupt bug and warning oops
USB: ftdi_sio: Keep going when write errors are encountered.
USB: musb_gadget: fix STALL handling
USB: EHCI: don't send Clear-TT-Buffer following a STALL
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
tty/of_serial: add missing ns16550a id
bcm63xx_uart: Fix serial driver compile breakage.
tty_port: handle the nonblocking open of a dead port corner case
Linus Torvalds [Tue, 1 Dec 2009 16:26:44 +0000 (08:26 -0800)]
Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
MIPS: Loongson: Switch from flatmem to sparsemem
MIPS: Loongson: Disallow 4kB pages
MIPS: Add missing definition for MADV_HWPOISON.
MIPS: Fix build error if __xchg() is not getting inlined.
MIPS: IP22/IP28 Disable early printk to fix boot problems on some systems.
Wu Zhangjin [Tue, 1 Dec 2009 06:55:25 +0000 (14:55 +0800)]
MIPS: Loongson: Disallow 4kB pages
Currently, with PAGE_SIZE_4KB, the kernel for loongson will hang on:
Kernel panic - not syncing: Attempted to kill init!
The possible reason is the cache aliases problem:
Loongson 2F has 64kb, 4 way L1 Cache, the way size is 16kb, which is bigger
then 4kb. so, If using 4kb page size, there is cache aliases problem.
To avoid this kind of problem, extra cache flushing. The 2nd possible
solution is 16kb page size which avoids cache aliases without the need for
extra cache flushes. So we disable 4kB pages until the aliasing issue is
solved.
Ralf Baechle [Tue, 24 Nov 2009 13:16:02 +0000 (13:16 +0000)]
MIPS: Fix build error if __xchg() is not getting inlined.
If __xchg() is not getting inlined the outline version of the function
will have a reference to __xchg_called_with_bad_pointer() which does not
exist remaining. Fixed by using BUILD_BUG_ON() to check for allowable
operand sizes.
Martin Michlmayr [Thu, 19 Nov 2009 16:40:09 +0000 (16:40 +0000)]
MIPS: IP22/IP28 Disable early printk to fix boot problems on some systems.
Some Debian users have reported that the kernel hangs early during boot on
some IP22 systems. Thomas Bogendoerfer found that this is due to a "bad
interaction between CONFIG_EARLY_PRINTK and overwritten prom memory during
early boot". Since there's no fix yet, disable CONFIG_EARLY_PRINTK for now.
Signed-off-by: Martin Michlmayr <tbm@cyrius.com> Cc: linux-mips@linux-mips.org Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Patchwork: http://patchwork.linux-mips.org/patch/702/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Linus Torvalds [Tue, 1 Dec 2009 15:36:23 +0000 (07:36 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha-2.6:
alpha: Fixup last users of irq_chip->typename
Alpha: Rearrange thread info flags fixing two regressions
arch/alpha/kernel: Add kmalloc NULL tests
arch/alpha/kernel/sys_ruffian.c: Use DIV_ROUND_CLOSEST
David Howells [Tue, 1 Dec 2009 13:52:08 +0000 (13:52 +0000)]
SLOW_WORK: Fix the CONFIG_MODULES=n case
Commits 3d7a641 ("SLOW_WORK: Wait for outstanding work items belonging to a
module to clear") introduced some code to make sure that all of a module's
slow-work items were complete before that module was removed, and commit 3bde31a ("SLOW_WORK: Allow a requeueable work item to sleep till the thread is
needed") further extended that, breaking it in the process if CONFIG_MODULES=n:
CC kernel/slow-work.o
kernel/slow-work.c: In function 'slow_work_execute':
kernel/slow-work.c:313: error: 'slow_work_thread_processing' undeclared (first use in this function)
kernel/slow-work.c:313: error: (Each undeclared identifier is reported only once
kernel/slow-work.c:313: error: for each function it appears in.)
kernel/slow-work.c: In function 'slow_work_wait_for_items':
kernel/slow-work.c:950: error: 'slow_work_unreg_sync_lock' undeclared (first use in this function)
kernel/slow-work.c:951: error: 'slow_work_unreg_wq' undeclared (first use in this function)
kernel/slow-work.c:961: error: 'slow_work_unreg_work_item' undeclared (first use in this function)
kernel/slow-work.c:974: error: 'slow_work_unreg_module' undeclared (first use in this function)
kernel/slow-work.c:977: error: 'slow_work_thread_processing' undeclared (first use in this function)
make[1]: *** [kernel/slow-work.o] Error 1
Fix this by:
(1) Extracting the bits of slow_work_execute() that are contingent on
CONFIG_MODULES, and the bits that should be, into inline functions and
placing them into the #ifdef'd section that defines the relevant variables
and adding stubs for moduleless kernels. This allows the removal of some
#ifdefs.
(2) #ifdef'ing out the contents of slow_work_wait_for_items() in moduleless
kernels.
The four functions related to handling module unloading synchronisation (and
their associated variables) could be offloaded into a separate .c file, but
each function is only used once and three of them are tiny, so doing so would
prevent them from being inlined.
David Howells [Tue, 1 Dec 2009 13:38:45 +0000 (13:38 +0000)]
9p: fix build breakage introduced by FS-Cache
While building 2.6.32-rc8-git2 for Fedora I noticed the following thinko
in commit 201a15428bd54f83eccec8b7c64a04b8f9431204 ("FS-Cache: Handle
pages pending storage that get evicted under OOM conditions"):
fs/9p/cache.c: In function '__v9fs_fscache_release_page':
fs/9p/cache.c:346: error: 'vnode' undeclared (first use in this function)
fs/9p/cache.c:346: error: (Each undeclared identifier is reported only once
fs/9p/cache.c:346: error: for each function it appears in.)
make[2]: *** [fs/9p/cache.o] Error 1
Fix the 9P filesystem to correctly construct the argument to
fscache_maybe_release_page().
Mark Brown [Mon, 30 Nov 2009 13:24:18 +0000 (13:24 +0000)]
mfd: Correct WM831X_MAX_ISEL_VALUE
There was confusion between the array size and the highest ISEL
value possible.
Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
NeilBrown [Tue, 1 Dec 2009 06:30:59 +0000 (17:30 +1100)]
md: revert incorrect fix for read error handling in raid1.
commit 4706b349f was a forward port of a fix that was needed
for SLES10. But in fact it is not needed in mainline because
the earlier commit dd00a99e7a fixes the same problem in a
better way.
Further, this commit introduces a bug in the way it interacts with
the automatic read-error-correction. If, after a read error is
successfully corrected, the same disk is chosen to re-read - the
re-read won't be attempted but an error will be returned instead.
After reverting that commit, there is the possibility that a
read error on a read-only array (where read errors cannot
be corrected as that requires a write) will repeatedly read the same
device and continue to get an error.
So in the "Array is readonly" case, fail the drive immediately on
a read error.
Thomas Gleixner [Tue, 1 Dec 2009 03:51:31 +0000 (22:51 -0500)]
alpha: Fixup last users of irq_chip->typename
The typename member of struct irq_chip was kept for migration purposes
and is obsolete since more than 2 years. Fix up the leftovers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Henderson <rth@twiddle.net> Cc: linux-alpha@vger.kernel.org Signed-off-by: Matt Turner <mattst88@gmail.com>
Michael Cree [Tue, 1 Dec 2009 03:44:40 +0000 (22:44 -0500)]
Alpha: Rearrange thread info flags fixing two regressions
The removal of the TIF_NOTIFY_RESUME flag, commit a583f1b54249b
"remove unused TIF_NOTIFY_RESUME flag," resulted in incorrect
setting of the unaligned access control flags by the prctl syscall.
The re-addition of the TIF_NOTIFY_RESUME flag, commit d0420c83f39f
"KEYS: Extend TIF_NOTIFY_RESUME to (almost) all architectures [try #6]"
further caused problems, namely incorrect operands to assembler code
as evidenced by:
AS arch/alpha/kernel/entry.o
arch/alpha/kernel/entry.S: Assembler messages:
arch/alpha/kernel/entry.S:326: Warning: operand out of range
(0x0000000000000406 is not between 0x0000000000000000 and
0x00000000000000ff)
Both regressions fixed by (1) rearranging TIF_NOTIFY_RESUME flag to be
in lower 8 bits of the thread info flags, and (2) making sure that
ALPHA_UAC_SHIFT matches the rearrangement of the thread info flags.
Signed-off-by: Michael Cree <mcree@orcon.net.nz> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: David Howells <dhowells@redhat.com>, Signed-off-by: Matt Turner <mattst88@gmail.com>
Gernot Hillier [Fri, 27 Nov 2009 12:49:23 +0000 (13:49 +0100)]
USB: Add support for Mobilcom Debitel USB UMTS Surf-Stick to option driver
This patch adds the vendor and device id for the Mobilcom Debitel UMTS surf
stick (a.k.a. 4G Systems XSStick W14, MobiData MBD-200HU, ...).
To see these ids, you need to switch the stick to modem operation first
with the help of usb_modeswitch. This makes it switch from 1c9e:f000 to
1c9e:9603 and thus be recognized by the option driver.
Oliver Neukum [Fri, 27 Nov 2009 14:17:59 +0000 (15:17 +0100)]
USB: work around for EHCI with quirky periodic schedules
a quirky chipset needs periodic schedules to run for a minimum
time before they can be disabled again. This enforces the requirement
with a time stamp and a calculated delay
Daniel Glöckner [Tue, 17 Nov 2009 09:52:57 +0000 (15:22 +0530)]
USB: musb: Fix CPPI IRQs not being signaled
On tx channel abort a cppi interrupt is generated for a short time by
setting the lowest bit of the TCPPICOMPPTR register. It is then reset
immediately by clearing the bit. When the interrupt handler is run,
it does not detect an interrupt in the TCPPIMSKSR or RCPPIMSKSR
registers and thus exits early without writing the TCPPIEOIR register.
It appears that this inhibits further cppi interrupts until the handler
is called by chance, f.ex. from davinci_interrupt().
By moving the unmasking of the interrupt below the writes to
TCPPICOMPPTR, no interrupt is generated and no write to TCPPIEOIR is
necessary.
Daniel Glöckner [Tue, 17 Nov 2009 09:52:56 +0000 (15:22 +0530)]
USB: musb: respect usb_request->zero in control requests
In gadget mode the answer to a control request should be followed by
a zero-length packet if the amount transferred is an exact multiple of
the endpoint's packet size and the requests has its "zero" flag set.
This patch prevents the request from being immediately removed from the
queue when a control IN transfer ends on a full packet and "zero" is set.
The next time ep0_txstate is entered, a zero-length packet is queued and
the request is removed as fifo_count is 0.
Thomas Dahlmann [Tue, 17 Nov 2009 22:18:27 +0000 (14:18 -0800)]
usb: amd5536udc: fixed shared interrupt bug and warning oops
- fixed shared interrupt bug reported by Vadim Lobanov
- fixed possible warning oops on driver unload when connected
- prevent interrupt flood in PIO mode ("modprobe amd5536udc use_dma=0")
when using gadget ether
Signed-off-by: Thomas Dahlmann <dahlmann.thomas@arcor.de> Cc: Robert Richter <robert.richter@amd.com> Cc: David Brownell <david-b@pacbell.net> Cc: stable <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
USB: ftdi_sio: Keep going when write errors are encountered.
The use of urb->actual_length to update tx_outstanding_bytes
implicitly assumes that the number of bytes actually written is the
same as the number of bytes we tried to write. On error that
assumption is violated so just use transfer_buffer_length the number
of bytes we intended to write to the device.
If an error occurs we need to fall through and call
usb_serial_port_softint to wake up processes waiting in
tty_wait_until_sent.
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Sergei Shtylyov [Wed, 18 Nov 2009 19:51:18 +0000 (22:51 +0300)]
USB: musb_gadget: fix STALL handling
The driver incorrectly cancels the mass-storage device CSW request
(which leads to device reset) due to giving back URB at the head of
endpoint's queue after sending each STALL handshake; stop doing that
and start checking for the queue being non-empty before stalling an
endpoint and disallowing stall in such case in musb_gadget_set_halt()
like the other gadget drivers do.
Moreover, the driver starts Rx request despite of the endpoint being
halted -- fix this by moving the SendStall bit check from musb_g_rx()
to rxstate(). And we also sometimes get into rxstate() with DMA still
active after clearing an endpoint's halt (not clear why), so bail out
in this case, similarly to what txstate() does...
While at it, also do the following changes :
- in musb_gadget_set_halt(), remove pointless Tx FIFO flushing (the
driver does not allow stalling with non-empty Tx FIFO anyway);
- in rxstate(), stop pointlessly zeroing the 'csr' variable;
- in musb_gadget_set_halt(), move the 'done' label to a more proper
place;
- in musb_g_rx(), eliminate the 'done' label completely...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Cc: <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Alan Stern [Wed, 18 Nov 2009 16:37:15 +0000 (11:37 -0500)]
USB: EHCI: don't send Clear-TT-Buffer following a STALL
This patch (as1304) fixes a regression in ehci-hcd. Evidently some
hubs don't handle Clear-TT-Buffer requests correctly, so we should
avoid sending them when they don't appear to be absolutely necessary.
The reported symptom is that output on a downstream audio device cuts
out because the hub stops relaying isochronous packets.
The patch prevents Clear-TT-Buffer requests from being sent following
a STALL handshake. In theory a STALL indicates either that the
downstream device sent a STALL or that no matching TT buffer could be
found. In either case, the transfer is completed and the TT buffer
does not remain busy, so it doesn't need to be cleared.
Also, the patch fixes a minor flaw in the code that actually sends the
Clear-TT-Buffer requests. Although the pipe direction isn't really
used for control transfers, it should be a Send rather than a Receive.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Javier Kohen <jkohen@users.sourceforge.net> CC: David Brownell <david-b@pacbell.net> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
projects / linux-beck.git / log