Re: [PATCH 8/8] scsi: ufs: Check for completion from the timeout handler

Bart Van Assche
2024-06-21T17:23:38Z

On 6/20/24 11:54 PM, Peter Wang (王信友) wrote:
> Unable to handle kernel NULL pointer dereference at virtual address
> 0000000000000194
> pc : [0xffffffddd7a79bf8] blk_mq_unique_tag+0x8/0x14
> lr : [0xffffffddd6155b84] ufshcd_mcq_req_to_hwq+0x1c/0x40
> [ufs_mediatek_mod_ise]
> do_mem_abort+0x58/0x118
> el1_abort+0x3c/0x5c
> el1h_64_sync_handler+0x54/0x90
> el1h_64_sync+0x68/0x6c
> blk_mq_unique_tag+0x8/0x14
> ufshcd_err_handler+0xae4/0xfa8 [ufs_mediatek_mod_ise]
> process_one_work+0x208/0x4fc
> worker_thread+0x228/0x438
> kthread+0x104/0x1d4
> ret_from_fork+0x10/0x20

Hi Peter,

The above backtrace can only occur with MCQ enabled. The backtrace I
posted was triggered on a system with a UFSHCI 3.0 controller (no MCQ).
So I think that the backtraces have different root causes and hence that
different patches are required to fix both crashes.

Thanks,

Bart.