kernel/linux.git/drivers, branch v3.8.8

tty: don't deadlock while flushing workqueue

2013-04-17T04:48:30+00:00

commit 852e4a8152b427c3f318bb0e1b5e938d64dcdc32 upstream. Since commit 89c8d91e31f2 ("tty: localise the lock") I see a dead lock in one of my dummy_hcd + g_nokia test cases. The first run was usually okay, the second often resulted in a splat by lockdep and the third was usually a dead lock. Lockdep complained about tty->hangup_work and tty->legacy_mutex taken both ways: | ====================================================== | [ INFO: possible circular locking dependency detected ] | 3.7.0-rc6+ #204 Not tainted | ------------------------------------------------------- | kworker/2:1/35 is trying to acquire lock: | (&tty->legacy_mutex){+.+.+.}, at: [] tty_lock_nested+0x36/0x80 | | but task is already holding lock: | ((&tty->hangup_work)){+.+...}, at: [] process_one_work+0x124/0x5e0 | | which lock already depends on the new lock. | | the existing dependency chain (in reverse order) is: | | -> #2 ((&tty->hangup_work)){+.+...}: | [] lock_acquire+0x84/0x190 | [] flush_work+0x3d/0x240 | [] tty_ldisc_flush_works+0x16/0x30 | [] tty_ldisc_release+0x21/0x70 | [] tty_release+0x35c/0x470 | [] __fput+0xd8/0x270 | [] ____fput+0xd/0x10 | [] task_work_run+0xb9/0xf0 | [] do_notify_resume+0x51/0x80 | [] work_notifysig+0x35/0x3b | | -> #1 (&tty->legacy_mutex/1){+.+...}: | [] lock_acquire+0x84/0x190 | [] mutex_lock_nested+0x6c/0x2f0 | [] tty_lock_nested+0x36/0x80 | [] tty_lock_pair+0x29/0x70 | [] tty_release+0x118/0x470 | [] __fput+0xd8/0x270 | [] ____fput+0xd/0x10 | [] task_work_run+0xb9/0xf0 | [] do_notify_resume+0x51/0x80 | [] work_notifysig+0x35/0x3b | | -> #0 (&tty->legacy_mutex){+.+.+.}: | [] __lock_acquire+0x1189/0x16a0 | [] lock_acquire+0x84/0x190 | [] mutex_lock_nested+0x6c/0x2f0 | [] tty_lock_nested+0x36/0x80 | [] tty_lock+0xf/0x20 | [] __tty_hangup+0x54/0x410 | [] do_tty_hangup+0x12/0x20 | [] process_one_work+0x1a3/0x5e0 | [] worker_thread+0x119/0x3a0 | [] kthread+0x94/0xa0 | [] ret_from_kernel_thread+0x1b/0x28 | |other info that might help us debug this: | |Chain exists of: | &tty->legacy_mutex --> &tty->legacy_mutex/1 --> (&tty->hangup_work) | | Possible unsafe locking scenario: | | CPU0 CPU1 | ---- ---- | lock((&tty->hangup_work)); | lock(&tty->legacy_mutex/1); | lock((&tty->hangup_work)); | lock(&tty->legacy_mutex); | | *** DEADLOCK *** Before the path mentioned tty_ldisc_release() look like this: | tty_ldisc_halt(tty); | tty_ldisc_flush_works(tty); | tty_lock(); As it can be seen, it first flushes the workqueue and then grabs the tty_lock. Now we grab the lock first: | tty_lock_pair(tty, o_tty); | tty_ldisc_halt(tty); | tty_ldisc_flush_works(tty); so lockdep's complaint seems valid. The earlier version of this patch took the ldisc_mutex since the other user of tty_ldisc_flush_works() (tty_set_ldisc()) did this. Peter Hurley then said that it is should not be requried. Since it wasn't done earlier, I dropped this part. The code under tty_ldisc_kill() was executed earlier with the tty lock taken so it is taken again. I was able to reproduce the deadlock on v3.8-rc1, this patch fixes the problem in my testcase. I didn't notice any problems so far. Signed-off-by: Sebastian Andrzej Siewior Cc: Alan Cox Cc: Peter Hurley Cc: Bryan O'Donoghue Signed-off-by: Greg Kroah-Hartman

udl: handle EDID failure properly.

2013-04-17T04:48:29+00:00

commit 1baee58638fc58248625255f5c5fcdb987f11b1f upstream. Don't oops seems proper. Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman

gpio: fix wrong checking condition for gpio range

2013-04-17T04:48:29+00:00

commit ad4e1a7caf937ad395ced585ca85a7d14395dc80 upstream. If index++ calculates from 0, the checking condition of "while (index++)" fails & it doesn't check any more. It doesn't follow the loop that used at here. Replace it by endless loop at here. Then it keeps parsing "gpio-ranges" property until it ends. Signed-off-by: Haojian Zhuang Reviewed-by: Linus Walleij Signed-off-by: Linus Walleij Signed-off-by: Jonghwan Choi Signed-off-by: Greg Kroah-Hartman

target: Fix incorrect fallthrough of ALUA Standby/Offline/Transition CDBs

2013-04-17T04:48:28+00:00

commit 30f359a6f9da65a66de8cadf959f0f4a0d498bba upstream. This patch fixes a bug where a handful of informational / control CDBs that should be allowed during ALUA access state Standby/Offline/Transition where incorrectly returning CHECK_CONDITION + ASCQ_04H_ALUA_TG_PT_*. This includes INQUIRY + REPORT_LUNS, which would end up preventing LUN registration when LUN scanning occured during these ALUA access states. Signed-off-by: Nicholas Bellinger Cc: Hannes Reinecke Signed-off-by: Greg Kroah-Hartman

SCSI: libsas: fix handling vacant phy in sas_set_ex_phy()

2013-04-17T04:48:28+00:00

commit d4a2618fa77b5e58ec15342972bd3505a1c3f551 upstream. If a result of the SMP discover function is PHY VACANT, the content of discover response structure (dr) is not valid. It sometimes happens that dr->attached_sas_addr can contain even SAS address of other phy. In such case an invalid phy is created, what causes NULL pointer dereference during destruction of expander's phys. So if a result of SMP function is PHY VACANT, the content of discover response structure (dr) must not be copied to phy structure. This patch fixes the following bug: BUG: unable to handle kernel NULL pointer dereference at 0000000000000030 IP: [] sysfs_find_dirent+0x12/0x90 Call Trace: [] sysfs_get_dirent+0x35/0x80 [] sysfs_unmerge_group+0x1e/0xb0 [] dpm_sysfs_remove+0x24/0x90 [] device_del+0x44/0x1d0 [] sas_rphy_delete+0x9/0x20 [scsi_transport_sas] [] sas_destruct_devices+0xe6/0x110 [libsas] [] process_one_work+0x16c/0x350 [] worker_thread+0x17a/0x410 [] kthread+0x96/0xa0 [] kernel_thread_helper+0x4/0x10 Signed-off-by: Lukasz Dorau Signed-off-by: Pawel Baldysiak Reviewed-by: Maciej Patelczyk Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman

Revert "brcmsmac: support 4313iPA"

2013-04-17T04:48:28+00:00

commit 54683441a92ebe20c5282465ea6f21e5e74d2974 upstream. This reverts commit b6fc28a158076ca2764edc9a6d1e1402f56e1c0c. This commit is reported to cause a regression in the support for some revisions of 4313 ePA devices. http://marc.info/?l=linux-wireless&m=136360340200943&w=2 Conflicts: drivers/net/wireless/brcm80211/brcmsmac/phy/phy_lcn.c Reported-by: David Herrmann Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman

dmaengine: omap-dma: Start DMA without delay for cyclic channels

2013-04-17T04:48:28+00:00

commit 765024697807ad1e1cac332aa891253ca4a339da upstream. cyclic DMA is only used by audio which needs DMA to be started without a delay. If the DMA for audio is started using the tasklet we experience random channel switch (to be more precise: channel shift). Reported-by: Peter Meerwald Signed-off-by: Peter Ujfalusi Acked-by: Santosh Shilimkar Acked-by: Russell King Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

Revert "tty/8250_pnp: serial port detection regression since v3.7"

2013-04-12T16:52:13+00:00

commit c12f9ea28e9fbe7b1f4cefc953bee33298370683 upstream. This reverts commit 77e372a3d82e5e4878ce1962207edd766773cc76. Checking for disabled resources board breaks detection pnp on another board "AMI UEFI implementation (Version: 0406 Release Date: 06/06/2012)". I'm working with the reporter of the original bug to write and test a better fix. https://bugzilla.redhat.com/show_bug.cgi?id=928246 Signed-off-by: Sean Young Signed-off-by: Greg Kroah-Hartman

rt2x00: rt2x00pci_regbusy_read() - only print register access failure once

2013-04-12T16:52:13+00:00

commit 83589b30f1e1dc9898986293c9336b8ce1705dec upstream. BugLink: http://bugs.launchpad.net/bugs/1128840 It appears that when this register read fails it never recovers, so I think there is no need to repeat the same error message ad infinitum. Signed-off-by: Tim Gardner Cc: Ivo van Doorn Cc: Gertjan van Wingerde Cc: Helmut Schaa Cc: "John W. Linville" Cc: linux-wireless@vger.kernel.org Cc: users@rt2x00.serialmonkey.com Cc: netdev@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman

mwifiex: complete last internal scan

2013-04-12T16:52:12+00:00

commit 21de979ecfc7b7f9442f8aea9a54b3ab670d0151 upstream. We are waiting on first scan command of internal scan request before association, so we should complete on last internal scan command response. Tested-by: Daniel Drake Tested-by: Marco Cesarano Signed-off-by: Bing Zhao Signed-off-by: Amitkumar Karwar Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman