Re: sata_via

[Rich West <Rich.West@wesmo.com>]

Jeff Garzik wrote:
> Rich West wrote:
>> On my mythtv backend system, the recordings volume tends to get pounded
>> rather hard (up to 5 recordings (some HD) at once with multiple frontend
>> systems reading from that same volume).  I recently (4 months ago)
>> upgraded the system to a motherboard that happened to have the VIA
>> chipset on it.
>>
>> Since that time, I have had some bizarre problems with that volume. 
>> After a seemingly random amount of time, the kernel would report an
>> error with the volume and put it in read-only mode.  However, it would
>> not really be in read-only mode, but it would be completely
>> inaccessible.  Unmounting the volume would be successful, but
>> re-mounting the volume would fail.
>>
>> I've replaced the drive (with an identical one), tested memory, changed
>> filesystems (it was LVM + ext3, then just ext3) and the problem 
>> persists.
>>
>> Running 2.6.24.4-64 (Fedora 8).
>>
>> A larger snippet from the messages log is (dmesg gets cleared after 
>> reboot):
>> Apr  3 16:47:27 mythtv1 kernel: ata4.00: exception Emask 0x0 SAct 0x0
>> SErr 0x0 action 0x2 frozen
>> Apr  3 16:47:27 mythtv1 kernel: ata4.00: cmd
>> c8/00:00:77:31:21/00:00:00:00:00/e1 tag 0 dma 131072 in
>> Apr  3 16:47:27 mythtv1 kernel:          res
>> 40/00:01:00:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout)
>> Apr  3 16:47:27 mythtv1 kernel: ata4.00: status: { DRDY }
>> Apr  3 16:47:27 mythtv1 kernel: ata4: soft resetting link
>> Apr  3 16:47:57 mythtv1 kernel: ata4.00: qc timeout (cmd 0x27)
>> Apr  3 16:47:57 mythtv1 kernel: ata4.00: failed to read native max
>> address (err_mask=0x4)
>> Apr  3 16:47:57 mythtv1 kernel: ata4.00: HPA support seems broken, will
>> skip HPA handling
>> Apr  3 16:47:57 mythtv1 kernel: ata4.00: revalidation failed (errno=-5)
>> Apr  3 16:47:57 mythtv1 kernel: ata4: failed to recover some devices,
>> retrying in 5 secs
>> Apr  3 16:48:02 mythtv1 kernel: ata4: soft resetting link
>> Apr  3 16:48:02 mythtv1 kernel: ata4.00: configured for UDMA/133
>> Apr  3 16:48:02 mythtv1 kernel: ata4: EH complete
>> Apr  3 16:49:02 mythtv1 kernel: ata4.00: exception Emask 0x0 SAct 0x0
>> SErr 0x0 action 0x2 frozen
>> Apr  3 16:49:02 mythtv1 kernel: ata4.00: cmd
>> c8/00:00:77:31:21/00:00:00:00:00/e1 tag 0 dma 131072 in
>> Apr  3 16:49:02 mythtv1 kernel:          res
>> 40/00:01:00:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout)
>> Apr  3 16:49:02 mythtv1 kernel: ata4.00: status: { DRDY }
>> Apr  3 16:49:02 mythtv1 kernel: ata4: soft resetting link
>> Apr  3 16:49:03 mythtv1 kernel: ata4.00: configured for UDMA/133
>> Apr  3 16:49:03 mythtv1 kernel: ata4: EH complete
>>
>> It is almost as if I am hitting some bug that is causing the drive to
>> fall off, but I really don't know where else to look or where else to
>> turn...
>>
>> I'm tempted to just go back to using a PATA drive (smaller.  :(  ) to
>> avoid the problem.  I'm just at a loss as to how it can actually be 
>> solved.
>
> This timeout/DRDY message has been a common one recently.  Some of the 
> issues causing this may be resolved in 2.6.25-rc, can you try that?
>
> Also, if you could build and test some older kernels to see when this 
> behavior first appeared, that would be quite helpful.
>
> Overall, a timeout _might_ be a problem with libata (the kernel SATA 
> drivers), or it _might_ be a problem with your system's interrupt 
> delivery (sometimes an ACPI or BIOS problem).  Try booting with 
> 'noapic' or 'acpi=off'.
>

Thanks for the quick response.

I know this problem was happening with all of the Fedora 7 supplied 
kernels (from initial release up until about a week ago) and has 
happened with each of the Fedora 8 supplied kernels.  I'll try rolling 
2.6.25-rc to see if the problem resurfaces.  Unfortunately, I don't know 
what collision of events causes this problem to erupt, but it usually 
happens within 7 days of a reboot (some times within hours of a reboot).

I'll give noapic a try, but (dumb question) what does acpi=off buy?

-Rich