Re: ahci port hangs while hard resetting link

[Tejun Heo <tj@kernel.org>]

Hello,

On 08/22/2010 11:10 PM, Anssi Hannula wrote:
> 22:52:18 : ata6: exception Emask 0x10 SAct 0x0 SErr 0x4050002 action 0xe 
> frozen
> 22:52:18 : ata6: irq_stat 0x00400040, connection status changed
> 22:52:18 : ata6: SError: { RecovComm PHYRdyChg CommWake DevExch }
> 22:52:18 : ata6: hard resetting link
> 22:52:28 : ata6: softreset failed (device not ready)
> 22:52:28 : ata6: hard resetting link
> 22:52:38 : ata6: softreset failed (device not ready)
> 22:52:38 : ata6: hard resetting link
> 22:52:49 : ata6: link is slow to respond, please be patient (ready=0)
> 22:53:13 : ata6: softreset failed (device not ready)
> 22:53:13 : ata6: limiting SATA link speed to 1.5 Gbps
> 22:53:13 : ata6: hard resetting link
> =====================
> I disconnect the drive for a few moments, but nothing is output by kernel.
> I reconnect it again, but again, nothing is output by the kernel.
> I run: echo "- - -" > 
> /sys/devices/pci0000:00/0000:00:1f.2/host5/scsi_host/host5/scan
> However, it appeared stuck and still no messages in the kernel log, so
> I disconnected the device again. Still nothing is output, and the
> following messages started to be output, indicating that the process
> had become stuck:

Looks like EH got stuck somehow.  Maybe the timeout calculation is
wrong?  Can you please trigger sysrq-t while the system is stuck and
post the result?

Thanks.

-- 
tejun