If 'argc' is zero we jump to the 'out:' label, but this leaks the
(unused) memory that 'dm_split_args()' allocated for 'argv' if the
string being split consisted entirely of whitespace. Jump to the
'out_argv:' label instead to free up that memory.
|kernel BUG at kernel/rtmutex.c:724!
|[<c029599c>] (rt_spin_lock_slowlock+0x108/0x2bc) from [<c01c2330>] (defer_bh+0x1c/0xb4)
|[<c01c2330>] (defer_bh+0x1c/0xb4) from [<c01c3afc>] (rx_complete+0x14c/0x194)
|[<c01c3afc>] (rx_complete+0x14c/0x194) from [<c01cac88>] (usb_hcd_giveback_urb+0xa0/0xf0)
|[<c01cac88>] (usb_hcd_giveback_urb+0xa0/0xf0) from [<c01e1ff4>] (musb_giveback+0x34/0x40)
|[<c01e1ff4>] (musb_giveback+0x34/0x40) from [<c01e2b1c>] (musb_advance_schedule+0xb4/0x1c0)
|[<c01e2b1c>] (musb_advance_schedule+0xb4/0x1c0) from [<c01e2ca8>] (musb_cleanup_urb.isra.9+0x80/0x8c)
|[<c01e2ca8>] (musb_cleanup_urb.isra.9+0x80/0x8c) from [<c01e2ed0>] (musb_urb_dequeue+0xec/0x108)
|[<c01e2ed0>] (musb_urb_dequeue+0xec/0x108) from [<c01cbb90>] (unlink1+0xbc/0xcc)
|[<c01cbb90>] (unlink1+0xbc/0xcc) from [<c01cc2ec>] (usb_hcd_unlink_urb+0x54/0xa8)
|[<c01cc2ec>] (usb_hcd_unlink_urb+0x54/0xa8) from [<c01c2a84>] (unlink_urbs.isra.17+0x2c/0x58)
|[<c01c2a84>] (unlink_urbs.isra.17+0x2c/0x58) from [<c01c2b44>] (usbnet_terminate_urbs+0x94/0x10c)
|[<c01c2b44>] (usbnet_terminate_urbs+0x94/0x10c) from [<c01c2d68>] (usbnet_stop+0x100/0x15c)
|[<c01c2d68>] (usbnet_stop+0x100/0x15c) from [<c020f718>] (__dev_close_many+0x94/0xc8)
defer_bh() takes the lock which is hold during unlink_urbs(). The safe
walk suggest that the skb will be removed from the list and this is done
by defer_bh() so it seems to be okay to drop the lock here.
Reported-by: AnÃbal Almeida Pinto <anibal.pinto@efacec.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Oliver Neukum <oliver@neukum.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolas Cavallari discovered that carl9170 has some
serious problems delivering data to sleeping stations.
It turns out that the driver was not honoring two
important flags (IEEE80211_TX_CTL_POLL_RESPONSE and
IEEE80211_TX_CTL_CLEAR_PS_FILT) which are set on
frames that should be sent although the receiving
station is still in powersave mode.
Reported-by: Nicolas Cavallari <Nicolas.Cavallari@lri.fr> Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On Access Point mode, when transmitting a packet, if the destination
station is in powersave mode, we abort transmitting the packet to the
device queue, but we do not reclaim the allocated memory. Given enough
packets, we can go in a state where there is no packet on the device
queue, but we think the device has no memory left, so no packet gets
transmitted, connections breaks and the AP stops working.
This undo the allocation done in the TX path when the station is in
power-save mode.
Signed-off-by: Nicolas Cavallari <cavallar@lri.fr> Acked-by: Christian Lamparter <chunkeey@googlemail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A global delay parameter has the side effect of being overwritten with 0 if a
single ZL2004 or ZL6105 is instantiated. If other chips supported by the same
driver are in the system, this will result in access errors for those chips.
To solve the problem, keep a per-instance copy of the delay parameter, and do
not change the original parameter.
Currently the module init function registers a platform_device and
only then allocates its IRQ and I/O region. This allows allocation to
race with the device's suspend() function. Instead, allocate
resources in the platform driver's probe() function and free them in
the remove() function.
The module exit function removes the platform device before the
character device that provides access to it. Change it to reverse the
order of initialisation.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xscale2 PMUs indicate overflow not via the PMU control register, but by
a separate overflow FLAG register instead.
This patch fixes the xscale2 PMU code to use this register to detect
to overflow and ensures that we clear any pending overflow when
disabling a counter.
Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The PMU IRQ handlers in perf assume that if a counter has overflowed
then perf must be responsible. In the paranoid world of crazy hardware,
this could be false, so check that we do have a valid event before
attempting to dereference NULL in the interrupt path.
Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When disabling a counter on an ARMv7 PMU, we should also clear the
overflow flag in case an overflow occurred whilst stopping the counter.
This prevents a spurious overflow being picked up later and leading to
either false accounting or a NULL dereference.
Reported-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On ARM, the PMU does not stop counting after an overflow and therefore
IRQ latency affects the new counter value read by the kernel. This is
significant for non-sampling runs where it is possible for the new value
to overtake the previous one, causing the delta to be out by up to
max_period events.
Commit a737823d ("ARM: 6835/1: perf: ensure overflows aren't missed due
to IRQ latency") attempted to fix this problem by allowing interrupt
handlers to pass an overflow flag to the event update function, causing
the overflow calculation to assume that the counter passed through zero
when going from prev to new. Unfortunately, this doesn't work when
overflow occurs on the perf_task_tick path because we have the flag
cleared and end up computing a large negative delta.
This patch removes the overflow flag from armpmu_event_update and
instead limits the sample_period to half of the max_period for
non-sampling profiling runs.
Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Erratum #743622 affects all r2 variants of the Cortex-A9 processor, so
ensure that the workaround is applied regardless of the revision.
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The "OMAPDSS: HDMI: PHY burnout fix" commit switched the HDMI driver
over to using a GPIO for plug detect. Unfortunately the ->detect()
method was not also updated, causing HDMI to no longer work for the
omapdrm driver (because it would actually check if a connection was
detected before attempting to enable display).
Signed-off-by: Rob Clark <rob@ti.com> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A hardware bug in the OMAP4 HDMI PHY causes physical damage to the board
if the HDMI PHY is kept powered on when the cable is not connected.
This patch solves the problem by adding hot-plug-detection into the HDMI
IP driver. This is not a real HPD support in the sense that nobody else
than the IP driver gets to know about the HPD events, but is only meant
to fix the HW bug.
The strategy is simple: If the display device is turned off by the user,
the PHY power is set to OFF. When the display device is turned on by the
user, the PHY power is set either to LDOON or TXON, depending on whether
the HDMI cable is connected.
The reason to avoid PHY OFF when the display device is on, but the cable
is disconnected, is that when the PHY is turned OFF, the HDMI IP is not
"ticking" and thus the DISPC does not receive pixel clock from the HDMI
IP. This would, for example, prevent any VSYNCs from happening, and
would thus affect the users of omapdss. By using LDOON when the cable is
disconnected we'll avoid the HW bug, but keep the HDMI working as usual
from the user's point of view.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
"hdmi_hpd" pin is muxed to INPUT and PULLUP, but the pin is not
currently used, and in the future when it is used, the pin is used as a
GPIO and is board specific, not an OMAP4 wide thing.
So remove the muxing for now.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The GPIO 60 on 4430sdp and Panda is not HPD GPIO, as currently marked in
the board files, but CT_CP_HPD, which is used to enable/disable HPD
functionality.
This patch renames the GPIO.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Patchset "ARM: orion: Refactor the MPP code common in the orion
platform" broke at least Orion5x based platforms. These platforms have
pins configured as GPIO when the selector is not 0x0. However the
common code assumes the selector is always 0x0 for a GPIO lines. It
then ignores the GPIO bits in the MPP definitions, resulting in that
Orion5x machines cannot correctly configure there GPIO lines.
The Fix removes the assumption that the selector is always 0x0.
In order that none GPIO configurations are correctly blocked,
Kirkwood and mv78xx0 MPP definitions are corrected to only set the
GPIO bits for GPIO configurations.
This third version, which does not contain any whitespace changes,
and is rebased on v3.3-rc2.
Signed-off-by: Andrew Lunn <andrew@lunn.ch> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Olof Johansson <olof@lixom.net>
The patch "ARM: orion: Consolidate USB platform setup code.", commit 4fcd3f374a928081d391cd9a570afe3b2c692fdc broke USB on TS-7800 and
other orion5x boards, because the wrong type of PHY was being passed
to the EHCI driver in the platform data. Orion5x needs EHCI_PHY_ORION
and all the others want EHCI_PHY_NA.
Allow the mach- code to tell the generic plat-orion code which USB PHY
enum to place into the platform data.
Version 2: Rebase to v3.3-rc2.
Reported-by: Ambroz Bizjak <ambrop7@gmail.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Ambroz Bizjak <ambrop7@gmail.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The latest vendor (non-mac80211) driver of 9/22/2011 shows some new
device IDs for rtl8192cu. In addition, some typos in the table are
fixed and one duplicate is removed.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The models do not resume correctly without acpi_sleep=nonvs.
Signed-off-by: Keng-Yu Lin <kengyu@canonical.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Enable use of the generic atomic64 implementation on AVR32 platforms.
Without this the kernel fails to build as the architecture does not
provide its version.
According to i.MX27 Reference Manual (p 1593) TXBIT0 bit selects
whether the most significant or the less significant part of the
data word written to the FIFO is transmitted.
As DSP_A is the same as DSP_B with a data offset of 1 bit, it
doesn't make any sense to remove TXBIT0 bit here.
Signed-off-by: Javier Martin <javier.martin@vista-silicon.com> Acked-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Recent enhancements in the bias management means that we might not be
in standby when the CODEC is idle and can have active widgets without
being in full power mode but the shutdown functionality assumes these
things. Add checks for the bias level at each stage so that we don't
do transitions other than the ON->PREPARE->STANDBY->OFF ones that the
drivers are expecting.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
VX900 can do hardware scaling for both IGAs in contrast to previous
hardware which could do it only for IGA2. This patch ensures that
we set the parameter for IGA2 and not for IGA1. This fixes hardware
scaling on VX900 until we have the infrastructure to support it for
both IGAs.
It used to be that minors where 8 bit. But now they
are actually 20 bit. So the fix is simplicity itself.
I've tested with 300 devices and all user-mode utils
work just fine. I have also mechanically added 10,000
to the ida (so devices are /dev/osd10000, /dev/osd10001 ...)
and was able to mkfs an exofs filesystem and access osds
from user-mode.
All the open-osd user-mode code uses the same library
to access devices through their symbolic names in
/dev/osdX so I'd say it's pretty safe. (Well tested)
This patch is very important because some of the systems
that will be deploying the 3.2 pnfs-objects code are larger
than 64 OSDs and will stop to work properly when reaching
that number.
This patch (as1531) adds a NOGET quirk for the Slim+ keyboard marketed
by AIREN. This keyboard seems to have a lot of bugs; NOGET works
around only one of them.
Fix a bug that causes a kernel panic when the number of received doorbells
is larger than number of entries in the inbound doorbell queue (current
default value = 512).
Another possible indication for this bug is large number of spurious
doorbells reported by tsi721 driver after reaching the queue size maximum.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Chul Kim <chul.kim@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> 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>
Git commit 25f269f17316549e "[S390] qdio: EQBS retry after CCQ 96"
introduced a regression in regard to the zfcp data router.
Revoke the incorrect simplification of the function call arguments
for the qdio handler to make the zfcp hardware data router working
again.
This is applicable to 3.2+ kernels.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Reviewed-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Timur Tabi <timur@freescale.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When trying to remove a key, we always send key
flags just setting the key type, not including
the multicast flag and the key ID. As a result,
whenever any key was removed, the unicast key 0
would be removed, causing a complete connection
loss after the second rekey (the first doesn't
cause a key removal). Fix the key removal code
to include the key ID and multicast flag, thus
removing the correct key.
Reported-by: Alexander Schnaidt <alex.schnaidt@googlemail.com> Tested-by: Alexander Schnaidt <alex.schnaidt@googlemail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dave Jones reports a few Fedora users hitting the BUG_ON(mm->nr_ptes...)
in exit_mmap() recently.
Quoting Hugh's discovery and explanation of the SMP race condition:
"mm->nr_ptes had unusual locking: down_read mmap_sem plus
page_table_lock when incrementing, down_write mmap_sem (or mm_users
0) when decrementing; whereas THP is careful to increment and
decrement it under page_table_lock.
Now most of those paths in THP also hold mmap_sem for read or write
(with appropriate checks on mm_users), but two do not: when
split_huge_page() is called by hwpoison_user_mappings(), and when
called by add_to_swap().
It's conceivable that the latter case is responsible for the
exit_mmap() BUG_ON mm->nr_ptes that has been reported on Fedora."
The simplest way to fix it without having to alter the locking is to make
split_huge_page() a noop in nr_ptes terms, so by counting the preallocated
pagetables that exists for every mapped hugepage. It was an arbitrary
choice not to count them and either way is not wrong or right, because
they are not used but they're still allocated.
Reported-by: Dave Jones <davej@redhat.com> Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Josh Boyer <jwboyer@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>
register_kprobe() aborts if the address of the new request falls in a
prohibited area (such as ftrace pouch, __kprobes annotated functions,
non-kernel text addresses, jump label text). We however don't return the
right error on this abort, resulting in a silent failure - incorrect
adding/reporting of kprobes ('perf probe do_fork+18' or 'perf probe
mcount' for instance).
In V2 we are incorporating Masami Hiramatsu's feedback.
This patch fixes it by returning -EINVAL upon failure.
While we are here, rename the label used for exit to be more appropriate.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Prashanth K Nageshappa <prashanth@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Jason Baron <jbaron@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>
Duplicate the data for iniAddac early on, to avoid having to do redundant
memcpy calls later. While we're at it, make AR5416 < v2.2 use the same
codepath. Fixes a reported crash on x86.
Signed-off-by: Felix Fietkau <nbd@openwrt.org> Reported-by: Magnus Määttä <magnus.maatta@logica.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rate control algorithms concludes the rate as invalid
with rate[i].idx < -1 , while they do also check for rate[i].count is
non-zero. it would be safer to zero initialize the 'count' field.
recently we had a ath9k rate control crash where the ath9k rate control
in ath_tx_status assumed to check only for rate[i].count being non-zero
in one instance and ended up in using invalid rate index for
'connection monitoring NULL func frames' which eventually lead to the crash.
thanks to Pavel Roskin for fixing it and finding the root cause.
https://bugzilla.redhat.com/show_bug.cgi?id=768639
Cc: Pavel Roskin <proski@gnu.org> 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>
The cifs code will attempt to open files on lookup under certain
circumstances. What happens though if we find that the file we opened
was actually a FIFO or other special file?
Currently, the open filehandle just ends up being leaked leading to
a dentry refcount mismatch and oops on umount. Fix this by having the
code close the filehandle on the server if it turns out not to be a
regular file. While we're at it, change this spaghetti if statement
into a switch too.
Reported-by: CAI Qian <caiqian@redhat.com> Tested-by: CAI Qian <caiqian@redhat.com> Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@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>
There is an issue when memcg unregisters events that were attached to
the same eventfd:
- On the first call mem_cgroup_usage_unregister_event() removes all
events attached to a given eventfd, and if there were no events left,
thresholds->primary would become NULL;
- Since there were several events registered, cgroups core will call
mem_cgroup_usage_unregister_event() again, but now kernel will oops,
as the function doesn't expect that threshold->primary may be NULL.
That's a good question whether mem_cgroup_usage_unregister_event()
should actually remove all events in one go, but nowadays it can't
do any better as cftype->unregister_event callback doesn't pass
any private event-associated cookie. So, let's fix the issue by
simply checking for threshold->primary.
FWIW, w/o the patch the following oops may be observed:
Bart Van Assche reported a hung fio process when either hot-removing
storage or when interrupting the fio process itself. The (pruned) call
trace for the latter looks like so:
The problem lies with the allocation batching code. It will
opportunistically allocate kiocbs, and then trim back the list of iocbs
when there is not enough room in the completion ring to hold all of the
events.
In the case above, what happens is that the pruning back of events ends
up freeing up the last active request and the context is marked as dead,
so it is thus responsible for waking up waiters. Unfortunately, the
code does not check for this condition, so we end up with a hung task.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Reported-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Bart Van Assche <bvanassche@acm.org> 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>
On i.MX53 we have to write a special SDHCI_CMD_ABORTCMD to the
SDHCI_TRANSFER_MODE register during a MMC_STOP_TRANSMISSION
command. This works for SD cards. However, with MMC cards
the MMC_SET_BLOCK_COUNT command is used instead, but this
needs the same handling. Fix MMC cards by testing for the
MMC_SET_BLOCK_COUNT command aswell. Tested on a custom i.MX53
board with a Transcend MMC+ card and eMMC.
The kernel started used MMC_SET_BLOCK_COUNT in 3.0, so this
is a regression for these boards introduced in 3.0; it should
go to 3.0/3.1/3.2-stable.
Some callbacks are set too early -- i.e. we can have dma capabilities but
we can't get a dma channel. So wait to get the dma channel before setting
callbacks and change logs consequently.
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>
: : I have noticed some user space problems (pulseaudio crashes in pthread
: : code, glibc/nptl test suite failures, java compiler freezes on SMP alpha
: : systems) that arise when using a 2.6.39 or later kernel on Alpha.
: : Bisecting between 2.6.38 and 2.6.39 (using glibc/nptl test suite as
: : criterion for good/bad kernel) eventually leads to:
: :
: : 8d7718aa082aaf30a0b4989e1f04858952f941bc is the first bad commit
: : commit 8d7718aa082aaf30a0b4989e1f04858952f941bc
: : Author: Michel Lespinasse <walken@google.com>
: : Date: Thu Mar 10 18:50:58 2011 -0800
: :
: : futex: Sanitize futex ops argument types
: :
: : Change futex_atomic_op_inuser and futex_atomic_cmpxchg_inatomic
: : prototypes to use u32 types for the futex as this is the data type the
: : futex core code uses all over the place.
: :
: : Looking at the commit I see there is a change of the uaddr argument in
: : the Alpha architecture specific code for futexes from int to u32, but I
: : don't see why this should cause a problem.
Richard Henderson said:
: futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
: u32 oldval, u32 newval)
: ...
: : "r"(uaddr), "r"((long)oldval), "r"(newval)
:
:
: There is no 32-bit compare instruction. These are implemented by
: consistently extending the values to a 64-bit type. Since the
: load instruction sign-extends, we want to sign-extend the other
: quantity as well (despite the fact it's logically unsigned).
:
: So:
:
: - : "r"(uaddr), "r"((long)oldval), "r"(newval)
: + : "r"(uaddr), "r"((long)(int)oldval), "r"(newval)
:
: should do the trick.
Michael said:
: This fixes the glibc test suite failures and the pulseaudio related
: crashes, but it does not fix the java compiiler lockups that I was (and
: are still) observing. That is some other problem.
Reported-by: Michael Cree <mcree@orcon.net.nz> Tested-by: Michael Cree <mcree@orcon.net.nz> Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Michel Lespinasse <walken@google.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Reviewed-by: Matt Turner <mattst88@gmail.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>
In the current kernel implementation, the Logitech Harmony 900 remote
control is matched to the cdc_ether driver through the generic
USB_CDC_SUBCLASS_MDLM entry. However, this device appears to be of the
pseudo-MDLM (Belcarra) type, rather than the standard one. This patch
blacklists the Harmony 900 from the cdc_ether driver and whitelists it for
the pseudo-MDLM driver in zaurus.
Signed-off-by: Scott Talbert <talbert@techie.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
s3c2410_dma_suspend suspends channels from 0 to dma_channels.
s3c2410_dma_resume resumes channels in reverse order. So
pointer should be decremented instead of being incremented.
Xommit ac5637611(genirq: Unmask oneshot irqs when thread was not woken)
fails to unmask when a !IRQ_ONESHOT threaded handler is handled by
handle_level_irq.
This happens because thread_mask is or'ed unconditionally in
irq_wake_thread(), but for !IRQ_ONESHOT interrupts never cleared. So
the check for !desc->thread_active fails and keeps the interrupt
disabled.
Keep the thread_mask zero for !IRQ_ONESHOT interrupts.
Document the thread_mask magic while at it.
Reported-and-tested-by: Sven Joachim <svenjoac@gmx.de> Reported-and-tested-by: Stefan Lippers-Hollmann <s.l-h@gmx.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The jack detection on WM1811 is often required during system suspend, add
it as another check when deciding if we should suspend.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The code is currently always checking the first resource of every
device only (several times.) This has been broken since the ACPI check
was added in February 2010 in commit 91fedede0338eb6203cdd618d8ece873fdb7c22c.
Fix the check to run on each resource individually, once.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is only one error code to return for a bad user-space buffer
pointer passed to a system call in the same address space as the
system call is executed, and that is EFAULT. Furthermore, the
low-level access routines, which catch most of the faults, return
EFAULT already.
Signed-off-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@hack.frob.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The regset common infrastructure assumed that regsets would always
have .get and .set methods, but not necessarily .active methods.
Unfortunately people have since written regsets without .set methods.
Rather than putting in stub functions everywhere, handle regsets with
null .get or .set methods explicitly.
Signed-off-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@hack.frob.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some codecs don't supply the mute amp-capabilities although the lowest
volume gives the mute. It'd be handy if the parser provides the mute
mixers in such a case.
This patch adds an extension amp-cap bit (which is used only in the
driver) to represent the min volume = mute state. Also modified the
amp cache code to support the fake mute feature when this bit is set
but the real mute bit is unset.
In addition, conexant cx5051 parser uses this new feature to implement
the missing mute controls.
When there are multiple input sources, the driver wrongly overwrites with
the value of the last input source on other slots at resume. Thus the
primary input source may be shown wrongly.
It turned out that a performance counter on AMD does not
count at all when the GO or HO bit is set in the control
register and SVM is disabled in EFER.
This patch works around this issue by masking out the HO bit
in the performance counter control register when SVM is not
enabled.
The GO bit is not touched because it is only set when the
user wants to count in guest-mode only. So when SVM is
disabled the counter should not run at all and the
not-counting is the intended behaviour.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Avi Kivity <avi@redhat.com> Cc: Stephane Eranian <eranian@google.com> Cc: David Ahern <dsahern@gmail.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Robert Richter <robert.richter@amd.com> Link: http://lkml.kernel.org/r/1330523852-19566-1-git-send-email-joerg.roedel@amd.com Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Enable the compat keyctl wrapper on s390x so that 32-bit s390 userspace can
call the keyctl() syscall.
There's an s390x assembly wrapper that truncates all the register values to
32-bits and this then calls compat_sys_keyctl() - but the latter only exists if
CONFIG_KEYS_COMPAT is enabled, and the s390 Kconfig doesn't enable it.
Without this patch, 32-bit calls to the keyctl() syscall are given an ENOSYS
error:
[root@devel4 ~]# keyctl show
Session Keyring
-3: key inaccessible (Function not implemented)
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: dan@danny.cz Cc: Carsten Otte <cotte@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The hardware generates an interrupt for every completed command in the
queue while the code assumed that it will only generate one interrupt
when the queue is empty. So, explicitly check if the queue is really
empty. This patch fixed problems which occurred due to high traffic on
the bus. While we are here, move the completion-initialization after the
parameter error checking.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Marek Vasut <marek.vasut@gmail.com> Cc: Lothar Waßmann <LW@KARO-electronics.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1. address has to be page aligned.
2. set_memory_x uses page size argument, not size.
Bug causes with following commit:
commit da28179b4e90dda56912ee825c7eaa62fc103797
Author: Mingarelli, Thomas <Thomas.Mingarelli@hp.com>
Date: Mon Nov 7 10:59:00 2011 +0100
watchdog: hpwdt: Changes to handle NX secure bit in 32bit path
The GPI_28 IRQ was not registered properly. The registration of
IRQ_LPC32XX_GPI_28 was added and the (wrong) IRQ_LPC32XX_GPI_11 at
LPC32XX_SIC1_IRQ(4) was replaced by IRQ_LPC32XX_GPI_28 (see manual of
LPC32xx / interrupt controller).
Signed-off-by: Roland Stigge <stigge@antcom.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes the initialization of the interrupt controller of the LPC32xx
by correctly setting up SIC1 and SIC2 instead of (wrongly) using the same value
as for the Main Interrupt Controller (MIC).
Signed-off-by: Roland Stigge <stigge@antcom.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The autofs compat handling fix caused a compile failure when
CONFIG_COMPAT isn't defined.
Instead of adding random #ifdef'fery in autofs, let's just make the
compat helpers earlier to use: without CONFIG_COMPAT, is_compat_task()
just hardcodes to zero.
We could probably do something similar for a number of other cases where
we have #ifdef's in code, but this is the low-hanging fruit.
Reported-and-tested-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the autofs protocol version 5 packet type was added in commit 5c0a32fc2cd0 ("autofs4: add new packet type for v5 communications"), it
obvously tried quite hard to be word-size agnostic, and uses explicitly
sized fields that are all correctly aligned.
However, with the final "char name[NAME_MAX+1]" array at the end, the
actual size of the structure ends up being not very well defined:
because the struct isn't marked 'packed', doing a "sizeof()" on it will
align the size of the struct up to the biggest alignment of the members
it has.
And despite all the members being the same, the alignment of them is
different: a "__u64" has 4-byte alignment on x86-32, but native 8-byte
alignment on x86-64. And while 'NAME_MAX+1' ends up being a nice round
number (256), the name[] array starts out a 4-byte aligned.
End result: the "packed" size of the structure is 300 bytes: 4-byte, but
not 8-byte aligned.
As a result, despite all the fields being in the same place on all
architectures, sizeof() will round up that size to 304 bytes on
architectures that have 8-byte alignment for u64.
Note that this is *not* a problem for 32-bit compat mode on POWER, since
there __u64 is 8-byte aligned even in 32-bit mode. But on x86, 32-bit
and 64-bit alignment is different for 64-bit entities, and as a result
the structure that has exactly the same layout has different sizes.
So on x86-64, but no other architecture, we will just subtract 4 from
the size of the structure when running in a compat task. That way we
will write the properly sized packet that user mode expects.
Not pretty. Sadly, this very subtle, and unnecessary, size difference
has been encoded in user space that wants to read packets of *exactly*
the right size, and will refuse to touch anything else.
Reported-and-tested-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
"nframes" comes from the user and "nframes * CD_FRAMESIZE_RAW" can wrap
on 32 bit systems. That would have been ok if we used the same wrapped
value for the copy, but we use a shifted value. We should just use the
checked version of copy_to_user() because it's not going to make a
difference to the speed.
The current epoll code can be tickled to run basically indefinitely in
both loop detection path check (on ep_insert()), and in the wakeup paths.
The programs that tickle this behavior set up deeply linked networks of
epoll file descriptors that cause the epoll algorithms to traverse them
indefinitely. A couple of these sample programs have been previously
posted in this thread: https://lkml.org/lkml/2011/2/25/297.
To fix the loop detection path check algorithms, I simply keep track of
the epoll nodes that have been already visited. Thus, the loop detection
becomes proportional to the number of epoll file descriptor and links.
This dramatically decreases the run-time of the loop check algorithm. In
one diabolical case I tried it reduced the run-time from 15 mintues (all
in kernel time) to .3 seconds.
Fixing the wakeup paths could be done at wakeup time in a similar manner
by keeping track of nodes that have already been visited, but the
complexity is harder, since there can be multiple wakeups on different
cpus...Thus, I've opted to limit the number of possible wakeup paths when
the paths are created.
This is accomplished, by noting that the end file descriptor points that
are found during the loop detection pass (from the newly added link), are
actually the sources for wakeup events. I keep a list of these file
descriptors and limit the number and length of these paths that emanate
from these 'source file descriptors'. In the current implemetation I
allow 1000 paths of length 1, 500 of length 2, 100 of length 3, 50 of
length 4 and 10 of length 5. Note that it is sufficient to check the
'source file descriptors' reachable from the newly added link, since no
other 'source file descriptors' will have newly added links. This allows
us to check only the wakeup paths that may have gotten too long, and not
re-check all possible wakeup paths on the system.
In terms of the path limit selection, I think its first worth noting that
the most common case for epoll, is probably the model where you have 1
epoll file descriptor that is monitoring n number of 'source file
descriptors'. In this case, each 'source file descriptor' has a 1 path of
length 1. Thus, I believe that the limits I'm proposing are quite
reasonable and in fact may be too generous. Thus, I'm hoping that the
proposed limits will not prevent any workloads that currently work to
fail.
In terms of locking, I have extended the use of the 'epmutex' to all
epoll_ctl add and remove operations. Currently its only used in a subset
of the add paths. I need to hold the epmutex, so that we can correctly
traverse a coherent graph, to check the number of paths. I believe that
this additional locking is probably ok, since its in the setup/teardown
paths, and doesn't affect the running paths, but it certainly is going to
add some extra overhead. Also, worth noting is that the epmuex was
recently added to the ep_ctl add operations in the initial path loop
detection code using the argument that it was not on a critical path.
Another thing to note here, is the length of epoll chains that is allowed.
Currently, eventpoll.c defines:
/* Maximum number of nesting allowed inside epoll sets */
#define EP_MAX_NESTS 4
This basically means that I am limited to a graph depth of 5 (EP_MAX_NESTS
+ 1). However, this limit is currently only enforced during the loop
check detection code, and only when the epoll file descriptors are added
in a certain order. Thus, this limit is currently easily bypassed. The
newly added check for wakeup paths, stricly limits the wakeup paths to a
length of 5, regardless of the order in which ep's are linked together.
Thus, a side-effect of the new code is a more consistent enforcement of
the graph depth.
Thus far, I've tested this, using the sample programs previously
mentioned, which now either return quickly or return -EINVAL. I've also
testing using the piptest.c epoll tester, which showed no difference in
performance. I've also created a number of different epoll networks and
tested that they behave as expectded.
I believe this solves the original diabolical test cases, while still
preserving the sane epoll nesting.
Signed-off-by: Jason Baron <jbaron@redhat.com> Cc: Nelson Elhage <nelhage@ksplice.com> Cc: Davide Libenzi <davidel@xmailserver.org> 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>
signalfd_cleanup() ensures that ->signalfd_wqh is not used, but
this is not enough. eppoll_entry->whead still points to the memory
we are going to free, ep_unregister_pollwait()->remove_wait_queue()
is obviously unsafe.
Change ep_poll_callback(POLLFREE) to set eppoll_entry->whead = NULL,
change ep_unregister_pollwait() to check pwq->whead != NULL under
rcu_read_lock() before remove_wait_queue(). We add the new helper,
ep_remove_wait_queue(), for this.
This works because sighand_cachep is SLAB_DESTROY_BY_RCU and because
->signalfd_wqh is initialized in sighand_ctor(), not in copy_sighand.
ep_unregister_pollwait()->remove_wait_queue() can play with already
freed and potentially reused ->sighand, but this is fine. This memory
must have the valid ->signalfd_wqh until rcu_read_unlock().
This patch is intentionally incomplete to simplify the review.
It ignores ep_unregister_pollwait() which plays with the same wqh.
See the next change.
epoll assumes that the EPOLL_CTL_ADD'ed file controls everything
f_op->poll() needs. In particular it assumes that the wait queue
can't go away until eventpoll_release(). This is not true in case
of signalfd, the task which does EPOLL_CTL_ADD uses its ->sighand
which is not connected to the file.
This patch adds the special event, POLLFREE, currently only for
epoll. It expects that init_poll_funcptr()'ed hook should do the
necessary cleanup. Perhaps it should be defined as EPOLLFREE in
eventpoll.
__cleanup_sighand() is changed to do wake_up_poll(POLLFREE) if
->signalfd_wqh is not empty, we add the new signalfd_cleanup()
helper.
ep_poll_callback(POLLFREE) simply does list_del_init(task_list).
This make this poll entry inconsistent, but we don't care. If you
share epoll fd which contains our sigfd with another process you
should blame yourself. signalfd is "really special". I simply do
not know how we can define the "right" semantics if it used with
epoll.
The main problem is, epoll calls signalfd_poll() once to establish
the connection with the wait queue, after that signalfd_poll(NULL)
returns the different/inconsistent results depending on who does
EPOLL_CTL_MOD/signalfd_read/etc. IOW: apart from sigmask, signalfd
has nothing to do with the file, it works with the current thread.
In short: this patch is the hack which tries to fix the symptoms.
It also assumes that nobody can take tasklist_lock under epoll
locks, this seems to be true.
Note:
- we do not have wake_up_all_poll() but wake_up_poll()
is fine, poll/epoll doesn't use WQ_FLAG_EXCLUSIVE.
- signalfd_cleanup() uses POLLHUP along with POLLFREE,
we need a couple of simple changes in eventpoll.c to
make sure it can't be "lost".
By hwmon sysfs interface convention, setting pwm_enable to zero sets a fan
to full speed. In the f75375s driver, this need be done by enabling
manual fan control, plus duty mode for the F875387 chip, and then setting
the maximum duty cycle. Fix a bug where the two necessary register writes
were swapped, effectively discarding the setting to full-speed.
This patch is just a minor update to one titled "imon: Input from ffdc
device type ignored" from Corinna Vinschen. An earlier patch to prevent
an oops when we got early callbacks also has the nasty side-effect of
wedging imon hardware, as we don't acknowledge the urb. Rework the check
slightly here to bypass processing the packet, as the driver isn't yet
fully initialized, but still acknowlege the urb and submit a new rx_urb.
Do this for both interfaces -- irrelevant for ffdc hardware, but
relevant for newer hardware, though newer hardware doesn't spew the
constant stream of data as soon as the hardware is initialized like the
older ffdc devices, so they'd be less likely to trigger this anyway...
Tested with both an ffdc device and an 0042 device.
The current use of /tmp for file lists is insecure. Put them under
$objtree/debian instead.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Acked-by: maximilian attems <max@stro.at> Signed-off-by: Michal Marek <mmarek@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Said commit adds a check whether the carrier link is ok. If the link is
not ok, the skb is freed and no new dma descriptor added to the rx dma
channel. This causes trouble during initialization when the carrier
status has not yet been updated. If a lot of packets are received while
netif_carrier_ok returns false, all dma descriptors are freed and the
rx dma transfer is stopped.
The bug occurs when the board is connected to a network with lots of
traffic and the ifconfig down/up is done, e.g., when reconfiguring
the interface with DHCP.
The bug can be reproduced by flood pinging the davinci board while doing
ifconfig eth0 down
ifconfig eth0 up
on the board.
After that, the rx path stops working and the overrun value reported
by ifconfig is counting up.
Set the RX FIFO flush watermark lower.
According to Federico and JMicron's reply,
setting it to 16QW would be stable on most platforms.
Otherwise, user might experience packet drop issue.
Reported-by: Federico Quagliata <federico@quagliata.org> Fixed-by: Federico Quagliata <federico@quagliata.org> Signed-off-by: Guo-Fu Tseng <cooldavid@cooldavid.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit f11017ec2d1859c661f4e2b12c4a8d250e1f47cf (2.6.37)
moved the fwmark variable in subcontext that is invalidated before
reaching the ip_vs_ct_in_get call. As vaddr is provided as pointer
in the param structure make sure the fwmark variable is in
same context. As the fwmark templates can not be matched,
more and more template connections are created and the
controlled connections can not go to single real server.
Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1520) fixes a bug in the SCSI layer's power management
implementation.
LUN scanning can be carried out asynchronously in do_scan_async(), and
sd uses an asynchronous thread for the time-consuming parts of disk
probing in sd_probe_async(). Currently nothing coordinates these
async threads with system sleep transitions; they can and do attempt
to continue scanning/probing SCSI devices even after the host adapter
has been suspended. As one might expect, the outcome is not ideal.
This is what the "prepare" stage of system suspend was created for.
After the prepare callback has been called for a host, target, or
device, drivers are not allowed to register any children underneath
them. Currently the SCSI prepare callback is not implemented; this
patch rectifies that omission.
For SCSI hosts, the prepare routine calls scsi_complete_async_scans()
to wait until async scanning is finished. It might be slightly more
efficient to wait only until the host in question has been scanned,
but there's currently no way to do that. Besides, during a sleep
transition we will ultimately have to wait until all the host scanning
has finished anyway.
For SCSI devices, the prepare routine calls async_synchronize_full()
to wait until sd probing is finished. The routine does nothing for
SCSI targets, because asynchronous target scanning is done only as
part of host scanning.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In do_scan_async(), calling scsi_autopm_put_host(shost) may reference
freed shost, and cause Posison overwitten warning.
Yes, this case can happen, for example, an USB is disconnected just
when do_scan_async() thread starts to run, then scsi_host_put() called
in scsi_finish_async_scan() will lead to shost be freed(because the
refcount of shost->shost_gendev decreases to 1 after USB disconnects),
at this point, if references shost again, system will show following
warning msg.
To make scsi_autopm_put_host(shost) always reference a valid shost,
put it just before scsi_host_put() in function
scsi_finish_async_scan().