linux-stable.git/drivers/dma, branch v4.4.166 Linux kernel stable tree dmaengine: dma-jz4780: Return error if not probed from DT 2018-11-21T08:27:33+00:00 Paul Cercueil paul@crapouillou.net 2018-08-29T21:32:44+00:00 7e41dd0f799dbe922cbcda56f2fdb0fbce6292ba [ Upstream commit 54f919a04cf221bc1601d1193682d4379dacacbd ] The driver calls clk_get() with the clock name set to NULL, which means that the driver could only work when probed from devicetree. From now on, we explicitly require the driver to be probed from devicetree. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Tested-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 54f919a04cf221bc1601d1193682d4379dacacbd ]

The driver calls clk_get() with the clock name set to NULL, which means
that the driver could only work when probed from devicetree. From now
on, we explicitly require the driver to be probed from devicetree.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver/dma/ioat: Call del_timer_sync() without holding prep_lock 2018-11-21T08:27:33+00:00 Waiman Long longman@redhat.com 2018-09-14T18:53:32+00:00 d7a7df4c972c5de069ecd0c23486147248db40a8 [ Upstream commit cfb03be6c7e8a1591285849c361d67b09f5149f7 ] The following lockdep splat was observed: [ 1222.241750] ====================================================== [ 1222.271301] WARNING: possible circular locking dependency detected [ 1222.301060] 4.16.0-10.el8+5.x86_64+debug #1 Not tainted [ 1222.326659] ------------------------------------------------------ [ 1222.356565] systemd-shutdow/1 is trying to acquire lock: [ 1222.382660] ((&ioat_chan->timer)){+.-.}, at: [<00000000f71e1a28>] del_timer_sync+0x5/0xf0 [ 1222.422928] [ 1222.422928] but task is already holding lock: [ 1222.451743] (&(&ioat_chan->prep_lock)->rlock){+.-.}, at: [<000000008ea98b12>] ioat_shutdown+0x86/0x100 [ioatdma] : [ 1223.524987] Chain exists of: [ 1223.524987] (&ioat_chan->timer) --> &(&ioat_chan->cleanup_lock)->rlock --> &(&ioat_chan->prep_lock)->rlock [ 1223.524987] [ 1223.594082] Possible unsafe locking scenario: [ 1223.594082] [ 1223.622630] CPU0 CPU1 [ 1223.645080] ---- ---- [ 1223.667404] lock(&(&ioat_chan->prep_lock)->rlock); [ 1223.691535] lock(&(&ioat_chan->cleanup_lock)->rlock); [ 1223.728657] lock(&(&ioat_chan->prep_lock)->rlock); [ 1223.765122] lock((&ioat_chan->timer)); [ 1223.784095] [ 1223.784095] *** DEADLOCK *** [ 1223.784095] [ 1223.813492] 4 locks held by systemd-shutdow/1: [ 1223.834677] #0: (reboot_mutex){+.+.}, at: [<0000000056d33456>] SYSC_reboot+0x10f/0x300 [ 1223.873310] #1: (&dev->mutex){....}, at: [<00000000258dfdd7>] device_shutdown+0x1c8/0x660 [ 1223.913604] #2: (&dev->mutex){....}, at: [<0000000068331147>] device_shutdown+0x1d6/0x660 [ 1223.954000] #3: (&(&ioat_chan->prep_lock)->rlock){+.-.}, at: [<000000008ea98b12>] ioat_shutdown+0x86/0x100 [ioatdma] In the ioat_shutdown() function: spin_lock_bh(&ioat_chan->prep_lock); set_bit(IOAT_CHAN_DOWN, &ioat_chan->state); del_timer_sync(&ioat_chan->timer); spin_unlock_bh(&ioat_chan->prep_lock); According to the synchronization rule for the del_timer_sync() function, the caller must not hold locks which would prevent completion of the timer's handler. The timer structure has its own lock that manages its synchronization. Setting the IOAT_CHAN_DOWN bit should prevent other CPUs from trying to use that device anyway, there is probably no need to call del_timer_sync() while holding the prep_lock. So the del_timer_sync() call is now moved outside of the prep_lock critical section to prevent the circular lock dependency. Signed-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit cfb03be6c7e8a1591285849c361d67b09f5149f7 ]

The following lockdep splat was observed:

[ 1222.241750] ======================================================
[ 1222.271301] WARNING: possible circular locking dependency detected
[ 1222.301060] 4.16.0-10.el8+5.x86_64+debug #1 Not tainted
[ 1222.326659] ------------------------------------------------------
[ 1222.356565] systemd-shutdow/1 is trying to acquire lock:
[ 1222.382660]  ((&ioat_chan->timer)){+.-.}, at: [<00000000f71e1a28>] del_timer_sync+0x5/0xf0
[ 1222.422928]
[ 1222.422928] but task is already holding lock:
[ 1222.451743]  (&(&ioat_chan->prep_lock)->rlock){+.-.}, at: [<000000008ea98b12>] ioat_shutdown+0x86/0x100 [ioatdma]
   :
[ 1223.524987] Chain exists of:
[ 1223.524987]   (&ioat_chan->timer) --> &(&ioat_chan->cleanup_lock)->rlock --> &(&ioat_chan->prep_lock)->rlock
[ 1223.524987]
[ 1223.594082]  Possible unsafe locking scenario:
[ 1223.594082]
[ 1223.622630]        CPU0                    CPU1
[ 1223.645080]        ----                    ----
[ 1223.667404]   lock(&(&ioat_chan->prep_lock)->rlock);
[ 1223.691535]                                lock(&(&ioat_chan->cleanup_lock)->rlock);
[ 1223.728657]                                lock(&(&ioat_chan->prep_lock)->rlock);
[ 1223.765122]   lock((&ioat_chan->timer));
[ 1223.784095]
[ 1223.784095]  *** DEADLOCK ***
[ 1223.784095]
[ 1223.813492] 4 locks held by systemd-shutdow/1:
[ 1223.834677]  #0:  (reboot_mutex){+.+.}, at: [<0000000056d33456>] SYSC_reboot+0x10f/0x300
[ 1223.873310]  #1:  (&dev->mutex){....}, at: [<00000000258dfdd7>] device_shutdown+0x1c8/0x660
[ 1223.913604]  #2:  (&dev->mutex){....}, at: [<0000000068331147>] device_shutdown+0x1d6/0x660
[ 1223.954000]  #3:  (&(&ioat_chan->prep_lock)->rlock){+.-.}, at: [<000000008ea98b12>] ioat_shutdown+0x86/0x100 [ioatdma]

In the ioat_shutdown() function:

	spin_lock_bh(&ioat_chan->prep_lock);
	set_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
	del_timer_sync(&ioat_chan->timer);
	spin_unlock_bh(&ioat_chan->prep_lock);

According to the synchronization rule for the del_timer_sync() function,
the caller must not hold locks which would prevent completion of the
timer's handler.

The timer structure has its own lock that manages its synchronization.
Setting the IOAT_CHAN_DOWN bit should prevent other CPUs from
trying to use that device anyway, there is probably no need to call
del_timer_sync() while holding the prep_lock. So the del_timer_sync()
call is now moved outside of the prep_lock critical section to prevent
the circular lock dependency.

Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dmaengine: pl330: fix irq race with terminate_all 2018-09-26T06:35:05+00:00 John Keeping john@metanate.com 2018-07-17T10:48:16+00:00 46c66ac938163769834ce38a298c65795ff9e0bc [ Upstream commit e49756544a21f5625b379b3871d27d8500764670 ] In pl330_update() when checking if a channel has been aborted, the channel's lock is not taken, only the overall pl330_dmac lock. But in pl330_terminate_all() the aborted flag (req_running==-1) is set under the channel lock and not the pl330_dmac lock. With threaded interrupts, this leads to a potential race: pl330_terminate_all pl330_update ------------------- ------------ lock channel entry lock pl330 _stop channel unlock pl330 lock pl330 check req_running != -1 req_running = -1 _start channel Signed-off-by: John Keeping <john@metanate.com> Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit e49756544a21f5625b379b3871d27d8500764670 ]

In pl330_update() when checking if a channel has been aborted, the
channel's lock is not taken, only the overall pl330_dmac lock.  But in
pl330_terminate_all() the aborted flag (req_running==-1) is set under
the channel lock and not the pl330_dmac lock.

With threaded interrupts, this leads to a potential race:

    pl330_terminate_all	        pl330_update
    -------------------         ------------
    lock channel
                                entry
    lock pl330
    _stop channel
    unlock pl330
                                lock pl330
                                check req_running != -1
    req_running = -1
                                _start channel

Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dmaengine: k3dma: Off by one in k3_of_dma_simple_xlate() 2018-08-24T11:26:57+00:00 Dan Carpenter dan.carpenter@oracle.com 2018-06-22T11:15:47+00:00 0430caf5ccc880dfacba544accbddc839d70ded1 [ Upstream commit c4c2b7644cc9a41f17a8cc8904efe3f66ae4c7ed ] The d->chans[] array has d->dma_requests elements so the > should be >= here. Fixes: 8e6152bc660e ("dmaengine: Add hisilicon k3 DMA engine driver") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit c4c2b7644cc9a41f17a8cc8904efe3f66ae4c7ed ]

The d->chans[] array has d->dma_requests elements so the > should be
>= here.

Fixes: 8e6152bc660e ("dmaengine: Add hisilicon k3 DMA engine driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dmaengine: pxa_dma: remove duplicate const qualifier 2018-08-06T14:24:40+00:00 Eric Engestrom eric.engestrom@imgtec.com 2016-04-25T09:47:56+00:00 b4cb2f0fd456f4eca58c9a84639aa8219c319cda commit 4e0def887d717598ae8062b46e55f9e00d3a5783 upstream. Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com> Acked-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Cc: Andrea Adami <andrea.adami@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4e0def887d717598ae8062b46e55f9e00d3a5783 upstream.

Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Cc: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all() 2018-06-06T14:46:22+00:00 Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com 2015-11-12T04:37:40+00:00 1cab402e6a4379f6dcfdc47f39ab832d909df277 commit d9f5efade2cfd729138a7cafb46d01044da40f5e upstream. This patch fixes an issue that list_for_each_entry() in usb_dmac_chan_terminate_all() is possible to cause endless loop because this will move own desc to the desc_freed. So, this driver should use list_for_each_entry_safe() instead of list_for_each_entry(). Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Biju Das <biju.das@bp.renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d9f5efade2cfd729138a7cafb46d01044da40f5e upstream.

This patch fixes an issue that list_for_each_entry() in
usb_dmac_chan_terminate_all() is possible to cause endless loop because
this will move own desc to the desc_freed. So, this driver should use
list_for_each_entry_safe() instead of list_for_each_entry().

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dmaengine: pl330: fix a race condition in case of threaded irqs 2018-05-30T05:49:14+00:00 Qi Hou qi.hou@windriver.com 2018-03-06T01:13:37+00:00 1f8b926275550719fb9f9541df1b039d8caa9e33 [ Upstream commit a3ca831249ca8c4c226e4ceafee04e280152e59d ] When booting up with "threadirqs" in command line, all irq handlers of the DMA controller pl330 will be threaded forcedly. These threads will race for the same list, pl330->req_done. Before the callback, the spinlock was released. And after it, the spinlock was taken. This opened an race window where another threaded irq handler could steal the spinlock and be permitted to delete entries of the list, pl330->req_done. If the later deleted an entry that was still referred to by the former, there would be a kernel panic when the former was scheduled and tried to get the next sibling of the deleted entry. The scenario could be depicted as below: Thread: T1 pl330->req_done Thread: T2 | | | | -A-B-C-D- | Locked | | | | Waiting Del A | | | -B-C-D- | Unlocked | | | | Locked Waiting | | | | Del B | | | | -C-D- Unlocked Waiting | | | Locked | get C via B \ - Kernel panic The kernel panic looked like as below: Unable to handle kernel paging request at virtual address dead000000000108 pgd = ffffff8008c9e000 [dead000000000108] *pgd=000000027fffe003, *pud=000000027fffe003, *pmd=0000000000000000 Internal error: Oops: 96000044 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 85 Comm: irq/59-66330000 Not tainted 4.8.24-WR9.0.0.12_standard #2 Hardware name: Broadcom NS2 SVK (DT) task: ffffffc1f5cc3c00 task.stack: ffffffc1f5ce0000 PC is at pl330_irq_handler+0x27c/0x390 LR is at pl330_irq_handler+0x2a8/0x390 pc : [<ffffff80084cb694>] lr : [<ffffff80084cb6c0>] pstate: 800001c5 sp : ffffffc1f5ce3d00 x29: ffffffc1f5ce3d00 x28: 0000000000000140 x27: ffffffc1f5c530b0 x26: dead000000000100 x25: dead000000000200 x24: 0000000000418958 x23: 0000000000000001 x22: ffffffc1f5ccd668 x21: ffffffc1f5ccd590 x20: ffffffc1f5ccd418 x19: dead000000000060 x18: 0000000000000001 x17: 0000000000000007 x16: 0000000000000001 x15: ffffffffffffffff x14: ffffffffffffffff x13: ffffffffffffffff x12: 0000000000000000 x11: 0000000000000001 x10: 0000000000000840 x9 : ffffffc1f5ce0000 x8 : ffffffc1f5cc3338 x7 : ffffff8008ce2020 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000001 x3 : dead000000000200 x2 : dead000000000100 x1 : 0000000000000140 x0 : ffffffc1f5ccd590 Process irq/59-66330000 (pid: 85, stack limit = 0xffffffc1f5ce0020) Stack: (0xffffffc1f5ce3d00 to 0xffffffc1f5ce4000) 3d00: ffffffc1f5ce3d80 ffffff80080f09d0 ffffffc1f5ca0c00 ffffffc1f6f7c600 3d20: ffffffc1f5ce0000 ffffffc1f6f7c600 ffffffc1f5ca0c00 ffffff80080f0998 3d40: ffffffc1f5ce0000 ffffff80080f0000 0000000000000000 0000000000000000 3d60: ffffff8008ce202c ffffff8008ce2020 ffffffc1f5ccd668 ffffffc1f5c530b0 3d80: ffffffc1f5ce3db0 ffffff80080f0d70 ffffffc1f5ca0c40 0000000000000001 3da0: ffffffc1f5ce0000 ffffff80080f0cfc ffffffc1f5ce3e20 ffffff80080bf4f8 3dc0: ffffffc1f5ca0c80 ffffff8008bf3798 ffffff8008955528 ffffffc1f5ca0c00 3de0: ffffff80080f0c30 0000000000000000 0000000000000000 0000000000000000 3e00: 0000000000000000 0000000000000000 0000000000000000 ffffff80080f0b68 3e20: 0000000000000000 ffffff8008083690 ffffff80080bf420 ffffffc1f5ca0c80 3e40: 0000000000000000 0000000000000000 0000000000000000 ffffff80080cb648 3e60: ffffff8008b1c780 0000000000000000 0000000000000000 ffffffc1f5ca0c00 3e80: ffffffc100000000 ffffff8000000000 ffffffc1f5ce3e90 ffffffc1f5ce3e90 3ea0: 0000000000000000 ffffff8000000000 ffffffc1f5ce3eb0 ffffffc1f5ce3eb0 3ec0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3ee0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f40: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f60: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3f80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3fa0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 3fc0: 0000000000000000 0000000000000005 0000000000000000 0000000000000000 3fe0: 0000000000000000 0000000000000000 0000000275ce3ff0 0000000275ce3ff8 Call trace: Exception stack(0xffffffc1f5ce3b30 to 0xffffffc1f5ce3c60) 3b20: dead000000000060 0000008000000000 3b40: ffffffc1f5ce3d00 ffffff80084cb694 0000000000000008 0000000000000e88 3b60: ffffffc1f5ce3bb0 ffffff80080dac68 ffffffc1f5ce3b90 ffffff8008826fe4 3b80: 00000000000001c0 00000000000001c0 ffffffc1f5ce3bb0 ffffff800848dfcc 3ba0: 0000000000020000 ffffff8008b15ae4 ffffffc1f5ce3c00 ffffff800808f000 3bc0: 0000000000000010 ffffff80088377f0 ffffffc1f5ccd590 0000000000000140 3be0: dead000000000100 dead000000000200 0000000000000001 0000000000000000 3c00: 0000000000000000 ffffff8008ce2020 ffffffc1f5cc3338 ffffffc1f5ce0000 3c20: 0000000000000840 0000000000000001 0000000000000000 ffffffffffffffff 3c40: ffffffffffffffff ffffffffffffffff 0000000000000001 0000000000000007 [<ffffff80084cb694>] pl330_irq_handler+0x27c/0x390 [<ffffff80080f09d0>] irq_forced_thread_fn+0x38/0x88 [<ffffff80080f0d70>] irq_thread+0x140/0x200 [<ffffff80080bf4f8>] kthread+0xd8/0xf0 [<ffffff8008083690>] ret_from_fork+0x10/0x40 Code: f2a00838 f9405763 aa1c03e1 aa1503e0 (f9000443) ---[ end trace f50005726d31199c ]--- Kernel panic - not syncing: Fatal exception in interrupt SMP: stopping secondary CPUs SMP: failed to stop secondary CPUs 0-1 Kernel Offset: disabled Memory Limit: none ---[ end Kernel panic - not syncing: Fatal exception in interrupt To fix this, re-start with the list-head after dropping the lock then re-takeing it. Reviewed-by: Frank Mori Hess <fmh6jj@gmail.com> Tested-by: Frank Mori Hess <fmh6jj@gmail.com> Signed-off-by: Qi Hou <qi.hou@windriver.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit a3ca831249ca8c4c226e4ceafee04e280152e59d ]

When booting up with "threadirqs" in command line, all irq handlers of the DMA
controller pl330 will be threaded forcedly. These threads will race for the same
list, pl330->req_done.

Before the callback, the spinlock was released. And after it, the spinlock was
taken. This opened an race window where another threaded irq handler could steal
the spinlock and be permitted to delete entries of the list, pl330->req_done.

If the later deleted an entry that was still referred to by the former, there would
be a kernel panic when the former was scheduled and tried to get the next sibling
of the deleted entry.

The scenario could be depicted as below:

  Thread: T1  pl330->req_done  Thread: T2
      |             |              |
      |          -A-B-C-D-         |
    Locked          |              |
      |             |           Waiting
    Del A           |              |
      |          -B-C-D-           |
    Unlocked        |              |
      |             |           Locked
    Waiting         |              |
      |             |            Del B
      |             |              |
      |           -C-D-         Unlocked
    Waiting         |              |
      |
    Locked
      |
   get C via B
      \
       - Kernel panic

The kernel panic looked like as below:

Unable to handle kernel paging request at virtual address dead000000000108
pgd = ffffff8008c9e000
[dead000000000108] *pgd=000000027fffe003, *pud=000000027fffe003, *pmd=0000000000000000
Internal error: Oops: 96000044 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 85 Comm: irq/59-66330000 Not tainted 4.8.24-WR9.0.0.12_standard #2
Hardware name: Broadcom NS2 SVK (DT)
task: ffffffc1f5cc3c00 task.stack: ffffffc1f5ce0000
PC is at pl330_irq_handler+0x27c/0x390
LR is at pl330_irq_handler+0x2a8/0x390
pc : [<ffffff80084cb694>] lr : [<ffffff80084cb6c0>] pstate: 800001c5
sp : ffffffc1f5ce3d00
x29: ffffffc1f5ce3d00 x28: 0000000000000140
x27: ffffffc1f5c530b0 x26: dead000000000100
x25: dead000000000200 x24: 0000000000418958
x23: 0000000000000001 x22: ffffffc1f5ccd668
x21: ffffffc1f5ccd590 x20: ffffffc1f5ccd418
x19: dead000000000060 x18: 0000000000000001
x17: 0000000000000007 x16: 0000000000000001
x15: ffffffffffffffff x14: ffffffffffffffff
x13: ffffffffffffffff x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000840
x9 : ffffffc1f5ce0000 x8 : ffffffc1f5cc3338
x7 : ffffff8008ce2020 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001
x3 : dead000000000200 x2 : dead000000000100
x1 : 0000000000000140 x0 : ffffffc1f5ccd590

Process irq/59-66330000 (pid: 85, stack limit = 0xffffffc1f5ce0020)
Stack: (0xffffffc1f5ce3d00 to 0xffffffc1f5ce4000)
3d00: ffffffc1f5ce3d80 ffffff80080f09d0 ffffffc1f5ca0c00 ffffffc1f6f7c600
3d20: ffffffc1f5ce0000 ffffffc1f6f7c600 ffffffc1f5ca0c00 ffffff80080f0998
3d40: ffffffc1f5ce0000 ffffff80080f0000 0000000000000000 0000000000000000
3d60: ffffff8008ce202c ffffff8008ce2020 ffffffc1f5ccd668 ffffffc1f5c530b0
3d80: ffffffc1f5ce3db0 ffffff80080f0d70 ffffffc1f5ca0c40 0000000000000001
3da0: ffffffc1f5ce0000 ffffff80080f0cfc ffffffc1f5ce3e20 ffffff80080bf4f8
3dc0: ffffffc1f5ca0c80 ffffff8008bf3798 ffffff8008955528 ffffffc1f5ca0c00
3de0: ffffff80080f0c30 0000000000000000 0000000000000000 0000000000000000
3e00: 0000000000000000 0000000000000000 0000000000000000 ffffff80080f0b68
3e20: 0000000000000000 ffffff8008083690 ffffff80080bf420 ffffffc1f5ca0c80
3e40: 0000000000000000 0000000000000000 0000000000000000 ffffff80080cb648
3e60: ffffff8008b1c780 0000000000000000 0000000000000000 ffffffc1f5ca0c00
3e80: ffffffc100000000 ffffff8000000000 ffffffc1f5ce3e90 ffffffc1f5ce3e90
3ea0: 0000000000000000 ffffff8000000000 ffffffc1f5ce3eb0 ffffffc1f5ce3eb0
3ec0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3ee0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3f00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3f20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3f40: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3f60: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3f80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3fa0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3fc0: 0000000000000000 0000000000000005 0000000000000000 0000000000000000
3fe0: 0000000000000000 0000000000000000 0000000275ce3ff0 0000000275ce3ff8
Call trace:
Exception stack(0xffffffc1f5ce3b30 to 0xffffffc1f5ce3c60)
3b20:                                   dead000000000060 0000008000000000
3b40: ffffffc1f5ce3d00 ffffff80084cb694 0000000000000008 0000000000000e88
3b60: ffffffc1f5ce3bb0 ffffff80080dac68 ffffffc1f5ce3b90 ffffff8008826fe4
3b80: 00000000000001c0 00000000000001c0 ffffffc1f5ce3bb0 ffffff800848dfcc
3ba0: 0000000000020000 ffffff8008b15ae4 ffffffc1f5ce3c00 ffffff800808f000
3bc0: 0000000000000010 ffffff80088377f0 ffffffc1f5ccd590 0000000000000140
3be0: dead000000000100 dead000000000200 0000000000000001 0000000000000000
3c00: 0000000000000000 ffffff8008ce2020 ffffffc1f5cc3338 ffffffc1f5ce0000
3c20: 0000000000000840 0000000000000001 0000000000000000 ffffffffffffffff
3c40: ffffffffffffffff ffffffffffffffff 0000000000000001 0000000000000007
[<ffffff80084cb694>] pl330_irq_handler+0x27c/0x390
[<ffffff80080f09d0>] irq_forced_thread_fn+0x38/0x88
[<ffffff80080f0d70>] irq_thread+0x140/0x200
[<ffffff80080bf4f8>] kthread+0xd8/0xf0
[<ffffff8008083690>] ret_from_fork+0x10/0x40
Code: f2a00838 f9405763 aa1c03e1 aa1503e0 (f9000443)
---[ end trace f50005726d31199c ]---
Kernel panic - not syncing: Fatal exception in interrupt
SMP: stopping secondary CPUs
SMP: failed to stop secondary CPUs 0-1
Kernel Offset: disabled
Memory Limit: none
---[ end Kernel panic - not syncing: Fatal exception in interrupt

To fix this, re-start with the list-head after dropping the lock then
re-takeing it.

Reviewed-by: Frank Mori Hess <fmh6jj@gmail.com>
Tested-by: Frank Mori Hess <fmh6jj@gmail.com>
Signed-off-by: Qi Hou <qi.hou@windriver.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dmaengine: rcar-dmac: fix max_chunk_size for R-Car Gen3 2018-05-30T05:49:02+00:00 Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com 2018-02-14T09:40:12+00:00 c0c5b3fbf9673e85c55f66e093df70a12d2f7ecd [ Upstream commit d716d9b702bb759dd6fb50804f10a174bd156d71 ] According to R-Car Gen3 Rev.0.80 manual, the DMATCR can be set to 16,777,215 as maximum. So, this patch fixes the max_chunk_size for safety on all of SoCs. Otherwise, a system may hang if the DMATCR is set to 0 on R-Car Gen3. Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit d716d9b702bb759dd6fb50804f10a174bd156d71 ]

According to R-Car Gen3 Rev.0.80 manual, the DMATCR can be set to
16,777,215 as maximum. So, this patch fixes the max_chunk_size for
safety on all of SoCs. Otherwise, a system may hang if the DMATCR
is set to 0 on R-Car Gen3.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dmaengine: at_xdmac: fix rare residue corruption 2018-04-24T07:32:08+00:00 Maxime Jayat maxime.jayat@mobile-devices.fr 2018-02-22T11:39:55+00:00 5c90515d520a6c23ed0605d7185f8cc2b47f799d commit c5637476bbf9bb86c7f0413b8f4822a73d8d2d07 upstream. Despite the efforts made to correctly read the NDA and CUBC registers, the order in which the registers are read could sometimes lead to an inconsistent state. Re-using the timeline from the comments, this following timing of registers reads could lead to reading NDA with value "@desc2" and CUBC with value "MAX desc1": INITD -------- ------------ |____________________| _______________________ _______________ NDA @desc2 \/ @desc3 _______________________/\_______________ __________ ___________ _______________ CUBC 0 \/ MAX desc1 \/ MAX desc2 __________/\___________/\_______________ | | | | Events:(1)(2) (3)(4) (1) check_nda = @desc2 (2) initd = 1 (3) cur_ubc = MAX desc1 (4) cur_nda = @desc2 This is allowed by the condition ((check_nda == cur_nda) && initd), despite cur_ubc and cur_nda being in the precise state we don't want. This error leads to incorrect residue computation. Fix it by inversing the order in which CUBC and INITD are read. This makes sure that NDA and CUBC are always read together either _before_ INITD goes to 0 or _after_ it is back at 1. The case where NDA is read before INITD is at 0 and CUBC is read after INITD is back at 1 will be rejected by check_nda and cur_nda being different. Fixes: 53398f488821 ("dmaengine: at_xdmac: fix residue corruption") Cc: stable@vger.kernel.org Signed-off-by: Maxime Jayat <maxime.jayat@mobile-devices.fr> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c5637476bbf9bb86c7f0413b8f4822a73d8d2d07 upstream.

Despite the efforts made to correctly read the NDA and CUBC registers,
the order in which the registers are read could sometimes lead to an
inconsistent state.

Re-using the timeline from the comments, this following timing of
registers reads could lead to reading NDA with value "@desc2" and
CUBC with value "MAX desc1":

 INITD --------                    ------------
              |____________________|
       _______________________  _______________
 NDA       @desc2             \/   @desc3
       _______________________/\_______________
       __________  ___________  _______________
 CUBC       0    \/ MAX desc1 \/  MAX desc2
       __________/\___________/\_______________
        |  |          |  |
Events:(1)(2)        (3)(4)

(1) check_nda = @desc2
(2) initd = 1
(3) cur_ubc = MAX desc1
(4) cur_nda = @desc2

This is allowed by the condition ((check_nda == cur_nda) && initd),
despite cur_ubc and cur_nda being in the precise state we don't want.

This error leads to incorrect residue computation.

Fix it by inversing the order in which CUBC and INITD are read. This
makes sure that NDA and CUBC are always read together either _before_
INITD goes to 0 or _after_ it is back at 1.
The case where NDA is read before INITD is at 0 and CUBC is read after
INITD is back at 1 will be rejected by check_nda and cur_nda being
different.

Fixes: 53398f488821 ("dmaengine: at_xdmac: fix residue corruption")
Cc: stable@vger.kernel.org
Signed-off-by: Maxime Jayat <maxime.jayat@mobile-devices.fr>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dmaengine: imx-sdma: Handle return value of clk_prepare_enable 2018-04-13T17:50:14+00:00 Arvind Yadav arvind.yadav.cs@gmail.com 2017-05-24T06:39:53+00:00 365d5376e2c42dad82625148cafa23723b4e3121 [ Upstream commit fb9caf370f4d0457789d13a1a1b110a8db846e5e ] clk_prepare_enable() can fail here and we must check its return value. Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit fb9caf370f4d0457789d13a1a1b110a8db846e5e ]

clk_prepare_enable() can fail here and we must check its return value.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>