Re: [PATCH] iommu/arm-smmu-v3: fix event handling soft lockup

[Will Deacon]

On Wed, 19 Jan 2022 07:07:54 +0000, Zhou Guanghui wrote:
> During event processing, events are read from the event queue one
> by one until the queue is empty.If the master device continuously
> requests address access at the same time and the SMMU generates
> events, the cyclic processing of the event takes a long time and
> softlockup warnings may be reported.
> 
> arm-smmu-v3 arm-smmu-v3.34.auto: event 0x0a received:
> arm-smmu-v3 arm-smmu-v3.34.auto: 	0x00007f220000280a
> arm-smmu-v3 arm-smmu-v3.34.auto: 	0x000010000000007e
> arm-smmu-v3 arm-smmu-v3.34.auto: 	0x00000000034e8670
> watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [irq/268-arm-smm:247]
> Call trace:
>  _dev_info+0x7c/0xa0
>  arm_smmu_evtq_thread+0x1c0/0x230
>  irq_thread_fn+0x30/0x80
>  irq_thread+0x128/0x210
>  kthread+0x134/0x138
>  ret_from_fork+0x10/0x1c
> Kernel panic - not syncing: softlockup: hung tasks
> 
> [...]

Applied to will (for-joerg/arm-smmu/updates), thanks!

[1/1] iommu/arm-smmu-v3: fix event handling soft lockup
      https://git.kernel.org/will/c/30de2b541af9

Cheers,
-- 
Will

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