* Re: BUG: SCSI SYNCHRONIZE_CACHE on driver unload
2004-08-05 23:02 BUG: SCSI SYNCHRONIZE_CACHE on driver unload Mark Lord
@ 2004-08-05 22:48 ` Randy.Dunlap
2004-08-05 23:13 ` Mark Lord
0 siblings, 1 reply; 3+ messages in thread
From: Randy.Dunlap @ 2004-08-05 22:48 UTC (permalink / raw)
To: Mark Lord; +Cc: linux-kernel, linux-scsi
On Thu, 05 Aug 2004 19:02:18 -0400 Mark Lord wrote:
| On module removal of a SCSI Low-Level Driver (LLD),
| the mid-layer tries to do a SYNCHRONIZE_CACHE
| command to each device on each host of that driver.
|
| But the command is issued *after* setting SHOST_CANCEL,
| which means that scsi_dispatch_cmd() will *always*
| fail the command inline, without passing to the LLD.
|
| This bug shows up only for hosts/drives which support
| a write-back caching scheme. For the more common
| write-thru scheme, the SYNCHRONIZE_CACHE command is
| never issued, so the bug never manifests.
Like this, when I unmount a zip drive (?):
Synchronizing SCSI cache for disk sde: <4>FAILED
status = 0, message = 00, host = 1, driver = 00
--
~Randy
^ permalink raw reply [flat|nested] 3+ messages in thread
* BUG: SCSI SYNCHRONIZE_CACHE on driver unload
@ 2004-08-05 23:02 Mark Lord
2004-08-05 22:48 ` Randy.Dunlap
0 siblings, 1 reply; 3+ messages in thread
From: Mark Lord @ 2004-08-05 23:02 UTC (permalink / raw)
To: Linux Kernel, linux-scsi
On module removal of a SCSI Low-Level Driver (LLD),
the mid-layer tries to do a SYNCHRONIZE_CACHE
command to each device on each host of that driver.
But the command is issued *after* setting SHOST_CANCEL,
which means that scsi_dispatch_cmd() will *always*
fail the command inline, without passing to the LLD.
This bug shows up only for hosts/drives which support
a write-back caching scheme. For the more common
write-thru scheme, the SYNCHRONIZE_CACHE command is
never issued, so the bug never manifests.
Cheers
--
Mark Lord
(hdparm keeper & the original "Linux IDE Guy")
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: BUG: SCSI SYNCHRONIZE_CACHE on driver unload
2004-08-05 22:48 ` Randy.Dunlap
@ 2004-08-05 23:13 ` Mark Lord
0 siblings, 0 replies; 3+ messages in thread
From: Mark Lord @ 2004-08-05 23:13 UTC (permalink / raw)
To: Randy.Dunlap; +Cc: linux-kernel, linux-scsi
Yup. That's the exact bug.
--
Mark Lord
(hdparm keeper & the original "Linux IDE Guy")
^ permalink raw reply [flat|nested] 3+ messages in thread
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2004-08-05 23:02 BUG: SCSI SYNCHRONIZE_CACHE on driver unload Mark Lord
2004-08-05 22:48 ` Randy.Dunlap
2004-08-05 23:13 ` Mark Lord
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