Re: Believed resolved: SATA kern-buffRd read slow: based on promise driver bug

[Robert Hancock <hancockr@shaw.ca>]

Linda Walsh wrote:
>    I seem to remember reading about some problems with Promise SATA & ACPI.
> Does this address that or is that a separate issue?  (Am using no-acpi for
> now, but would like to try acpi again if it may be fixed (last time I tried
> it with this card, "sdb" went "offline" (once it unmounted itself and
> refused to be remounted (no error...just nothing), and another it stayed
> mounted, but gave an I/O Error...so have been using no-acpi since).
> An ACPI error in bootup said:
> ACPI Exception (utmutex-0263): AE_BAD_PARAMETER, Thread EFFC2000 could 
> not acquire Mutex [3] [20070126]

Have you tried 2.6.24-rc6? If the problem still occurs there, you should 
post the full bootup log.

> 
>    Is the above bug mentioned/discussed in the linux-ide archives?  That
> and I'd like to find out why TCQ/NCQ doesn't work with the Seagate 
> drives --
> my guess, since they say queuedepth of 0/32, is that they are blacklisted
> as being drives that don't follow normal protocol or implement their
> own proprietary extensions?  Sigh.  Really a lame move (if that's the case)
> for Seagate, considering they usage they could likely get in server
> configs.  Maybe they want to push their SCSI/SAS drives?

Queue depth 0/32 means the drive supports a queue depth of 32 but the 
controller/driver don't support NCQ.

>    BTW, can SATA have DPO or FUA or are those limited to SCSI?
> Would it be a desirable future addition to remove the
> "doesn't support DPO or FUA" error message" on SATA drives if they are
> specific to SCSI?

ATA disks can have FUA support, but the support is disabled in libata by 
default. (There's a fua parameter on libata module to enable it I believe.)