Tejun Heo wrote:
02_libata_add-locking-to-ata_scsi_error.patch
SCSI EH can start before ata_qc_complete is completely
complete. so, latter part of ata_qc_complete can run
side-by-side with ->eng_timeout(), interfering EH.
This patch makes ata_scsi_error() to grab and release host_set
lock before invoking ->eng_timeout().
Note: host_failed decrementing and eh_cmd_q banging are moved
above ->eng_timeout() invocation such that they're done while
holding the lock.
I think it's better to follow a path that sets a "EH owns this port now"
flag inside spinlock,
spin_lock_irqsave()
ap->in_eh = 1;
spin_unlock_irqrestore()
and then check that flag in ata_qc_complete()
if (qc->ap->in_eh)
return; /* do nothing else with command */
so that for the case of a late interrupt, the interrupt handler should
acknowledge the interrupt, but not actually touch the ata_queued_cmd state.
Jeff
-
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
