Bug 15721 - mptsas cannot dectect hotplugged harddisks occasionally
Summary: mptsas cannot dectect hotplugged harddisks occasionally
Status: RESOLVED INSUFFICIENT_DATA
Alias: None
Product: IO/Storage
Classification: Unclassified
Component: SCSI (show other bugs)
Hardware: All Linux
: P1 high
Assignee: linux-scsi@vger.kernel.org
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-04-08 05:20 UTC by dujun
Modified: 2012-07-11 14:57 UTC (History)
4 users (show)

See Also:
Kernel Version: 2.6.32
Subsystem:
Regression: Yes
Bisected commit-id:


Attachments
debug info when unplug device (2.03 KB, text/plain)
2010-04-08 06:15 UTC, dujun
Details
debug info when hot plug device is detected (2.99 KB, text/plain)
2010-04-08 06:18 UTC, dujun
Details
debug info when hot plug device is not detected (1.02 KB, text/plain)
2010-04-08 06:21 UTC, dujun
Details
fix sata hotplug problem from lsi (1.31 KB, patch)
2010-04-13 09:15 UTC, dujun
Details | Diff

Description dujun 2010-04-08 05:20:00 UTC
with kernel 2.6.32 vanilla mptsas driver, the SATA disks connected through
sas backbone to 1068e hba card. sometimes the system cannot detect
hotplugged harddisk. after upgrading to lsi 4.22.00 driver, no
improvement at all. 
If we connect disks through a lsi 24x expander chip, there's no problem
detecting hotplugged disks. 
2.6.21 kernel mptsas driver doesn't has this problem.
Comment 1 dujun 2010-04-08 06:15:55 UTC
Created attachment 25910 [details]
debug info when unplug device
Comment 2 dujun 2010-04-08 06:18:20 UTC
Created attachment 25911 [details]
debug info when hot plug device is detected
Comment 3 dujun 2010-04-08 06:21:21 UTC
Created attachment 25912 [details]
debug info when hot plug device is not detected
Comment 4 Andrew Morton 2010-04-09 20:54:38 UTC
Recategorised to scsi, assigned to Eric.
Comment 5 dujun 2010-04-11 00:50:53 UTC
Comment on attachment 25912 [details]
debug info when hot plug device is not detected

this doesn't proceed to test_unit_ready as the correct hotplug sequence but directly to the mptsas_free_fw_event.
Comment 6 dujun 2010-04-13 09:15:51 UTC
Created attachment 25987 [details]
fix sata hotplug problem from lsi

This patch is from lsi. It seems that it makes situation much better. If we plug only one disk, it is always found now. (50 times testing passed successfully). However, if we plug several disks together, there are still one to three disks missing.
Comment 7 Andrew Morton 2010-04-13 19:18:03 UTC
Please don't send patches via bugzilla - it causes lots of problems with
our usual patch management and review processes.

Please send this patch via email as per Documentation/SubmittingPatches. 
Suitable recipients may be found via scripts/get_maintainer.pl.  Please
also cc myself on the email.

Thanks.
Comment 8 kashyap 2010-04-23 08:33:58 UTC
(In reply to comment #6)
> Created an attachment (id=25987) [details]
> fix sata hotplug problem from lsi
> 
> This patch is from lsi. It seems that it makes situation much better. If we
> plug only one disk, it is always found now. (50 times testing passed
> successfully). However, if we plug several disks together, there are still
> one
> to three disks missing.
LSI has plan to post this patch soon. we are doing more testing on this patch.
We are not seeing this issue(multiple SATA drivers hotplug) in our LAB. If you can provide me logs with and without debug level = 0x100000 I can provide my analysis. 
"echo 0x100000 > /sys/modules/mptbase/parameters/mpt_debug_level"

Thanks, Kashyap

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