SRU request for LP#210637
Colin Ian King
colin.king at canonical.com
Thu May 8 08:13:31 UTC 2008
Impact: Regression for sata_nv on Hardy - system reboots or causes XFS
filesystem shutdown due to errors.
Fix description: Patch to check for NV_ADMA_STAT_CMD_COMPLETE to handle
a completed command rather than checking for NV_ADMA_STAT_DONE.
Testcase: Turn off drive caching using hdparm -W 0 /dev/sda and exercise
the XFS filesystem on the drive (a HDS7250SASUN500G).
Author: Robert Hancock <hancockr at shaw.ca>
Date: Tue Jan 29 19:53:19 2008 -0600
sata_nv: fix for completion handling
This patch is based on an original patch from Kuan Luo of NVIDIA,
posted under subject "fixed a bug of adma in rhel4u5 with
His description follows. I've reworked it a bit to avoid some
repeated checks but it should be functionally identical.
"The patch is to solve the error message "ata1: CPB flags CMD err,
flags=0x11" when testing HDS7250SASUN500G in rhel4u5.
I tested this hd in 2.6.24-rc7 which needed to remove the mask in
blacklist to run the ncq and the same error also showed up.
I traced the bug and found that the interrupt finished a command
example, tag=0) when the driver got that adma status is
NV_ADMA_STAT_DONE and cpb->resp_flags is NV_CPB_RESP_DONE.
However, For this hd, the drive maybe didn't clear bit 0 at this
It meaned the hardware had not completely finished the command.
If at the same time the driver freed the command(tag 0) and sended
another command (tag 0), the error happened.
The notifier register is 32-bit register containing notifier value.
Value is bit vector containing one bit per tag number (0-31) in
corresponding bit positions (bit 0 is for tag 0, etc). When bit is
then ADMA indicates that command with corresponding tag number
So i added the check notifier code. Sometimes i saw that the
reg set some bits , but the adma status set
,not NV_ADMA_STAT_DONE. So i added the NV_ADMA_STAT_CMD_COMPLETE
Signed-off-by: Robert Hancock <hancockr at shaw.ca>
Signed-off-by: Jeff Garzik <jeff at garzik.org>
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