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

[Linda Walsh <lkml@tlinx.org>]

Mikael Pettersson wrote:
> Linda Walsh writes:
>  > Robert Hancock wrote:
>  > > Linda Walsh wrote:
>  > >>>> read rate began falling; at 128k block-reads-at-a-time or larger, it 
>  > >>>> drops below 20MB/s (only on buffered SATA).
>  > 
>  > But more importantly -- I notice a chronic error message associate
>  > with this drive that may be causing some or all of the problem:
>  > ---
>  > ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2
>  > ata1.00: port_status 0x20080000
>  > ata1.00: cmd c8/00:10:30:06:03/00:00:00:00:00/e0 tag 0 cdb 0x0 data 8192 in
>  >          res 50/00:00:3f:06:03/00:00:00:00:00/e0 Emask 0x2 (HSM violation)
>  > ata1: limiting SATA link speed to 1.5 Gbps
>
>
> Looks like the Promise ASIC SG bug. Apply
> <http://user.it.uu.se/~mikpe/linux/patches/sata_promise/patch-sata_promise-1-asic-sg-bug-fix-v3-2.6.23>
> and let us know if things improve.
>
> /Mikael
>   
---
    Yep!  Hope that's making it into a patch soon or, at least 2.6.24.
    Kernel buffered

    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]

    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?

    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?