Re: sata_mv port lockup on hotplug (kernel 2.6.38.2)
From: Tejun Heo <hidden>
Date: 2011-09-06 16:34:12
Also in:
lkml
Subsystem:
libata subsystem (serial and parallel ata drivers), the rest · Maintainers:
Damien Le Moal, Niklas Cassel, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2011-04-06 · Re: sata_mv port lockup on hotplug (kernel 2.6.38.2) · Alejandro Riveira Fernández <hidden>
Hello, On Tue, Sep 06, 2011 at 01:19:44PM +0100, Bruce Stenning wrote:
ata4: EH complete Waking error handler thread scsi_eh_wakeup: succeeded scsi_schedule_eh: succeeded scsi_restart_operations: waking up host to restart Error handler scsi_eh_3 sleeping
I think the following should fix the problem. The code there is from the time when libata shared scsi_host->host_lock. libata no longer does that so, in the current state, host_eh_scheduled can be cleared with actual pending EH condition. You should be able to reproduce the problem more easily by adding delay (something like mdelay(5)) before host_eh_scheduled clearing without the following patch applied. Thanks.
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index ed16fbe..e971784 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c@@ -771,6 +771,14 @@ void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap) /* process port suspend request */ ata_eh_handle_port_suspend(ap); + /* + * Single iteration complete. Clear SCSI EH scheduled + * state and check whether another iteration is necessary. + */ + spin_lock_irqsave(host->host_lock, flags); + host->host_eh_scheduled = 0; + spin_unlock_irqrestore(host->host_lock, flags); + /* Exception might have happened after ->error_handler * recovered the port but before this point. Repeat * EH in such case.
@@ -792,13 +800,6 @@ void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap) ata_for_each_link(link, ap, HOST_FIRST) memset(&link->eh_info, 0, sizeof(link->eh_info)); - /* Clear host_eh_scheduled while holding ap->lock such - * that if exception occurs after this point but - * before EH completion, SCSI midlayer will - * re-initiate EH. - */ - host->host_eh_scheduled = 0; - spin_unlock_irqrestore(ap->lock, flags); ata_eh_release(ap); } else {