Re: [PATCH v9 8/9] scsi: ufs: Fix a racing problem btw error handler and runtime PM ops

From: Can Guo
Date: Thu Aug 06 2020 - 00:54:04 EST


On 2020-08-05 09:31, Martin K. Petersen wrote:
Can,

Current IRQ handler blocks scsi requests before scheduling eh_work,
when error handler calls pm_runtime_get_sync, if ufshcd_suspend/resume
sends a scsi cmd, most likely the SSU cmd, since scsi requests are
blocked, pm_runtime_get_sync() will never return because
ufshcd_suspend/reusme is blocked by the scsi cmd. Some changes and
code re-arrangement can be made to resolve it.

CC [M] drivers/scsi/ufs/ufshcd.o
drivers/scsi/ufs/ufshcd.c: In function ‘ufshcd_queuecommand’:
drivers/scsi/ufs/ufshcd.c:2570:6: error: this statement may fall
through [-Werror=implicit-fallthrough=]
2570 | if (hba->pm_op_in_progress) {
| ^
drivers/scsi/ufs/ufshcd.c:2575:2: note: here
2575 | case UFSHCD_STATE_RESET:
| ^~~~
cc1: all warnings being treated as errors
make[3]: *** [scripts/Makefile.build:280: drivers/scsi/ufs/ufshcd.o] Error 1
make[2]: *** [scripts/Makefile.build:497: drivers/scsi/ufs] Error 2
make[1]: *** [scripts/Makefile.build:497: drivers/scsi] Error 2
make: *** [Makefile:1764: drivers] Error 2

Thanks Martin, will fix it in next version.

Can Guo.