On 6/24/24 1:54 AM, Peter Wang (王信友) wrote:
Your backtrace is Single doorbell mode. But I am curious that
how could it happen if complete a cmd twice and get null pointer
next time queuecommand? could you describe the exactly flow?
SCSI commands are completed only once. See also the code in the SCSI
core that sets the SCMD_STATE_COMPLETE bit:
$ git grep -nH 'test_and_set_bit(SCMD_STATE_COMPLETE'
drivers/scsi/scsi_error.c:362: if (test_and_set_bit(SCMD_STATE_COMPLETE,
&scmd->state))
drivers/scsi/scsi_lib.c:1716: if
(unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state)))
In other words, either the regular completion code is executed by
scsi_done_internal() or error handling is initiated by scsi_timeout().
Only one of the two happens.
The only exception is that .eh_timed_out() may be called concurrently
with the regular completion handler. Hence this patch for
ufshcd_eh_timed_out().
Bart.
