Hi all,
Any suggestion?
Thanks,
Chandra
On 2/4/10 12:59 PM, Grant Grundler wrote:
On Wed, Feb 3, 2010 at 7:24 PM, Tejun Heo<tj@xxxxxxxxxx> wrote:
On 02/04/2010 11:37 AM, Grant Grundler wrote:
I had two questions on that thread that never got answered:
http://markmail.org/message/snpekoj4qexrslk5
| How can we find out if anyone has the SEMB properly wired up?
| Would it be hard to make libata aware of "SEMB port not responding" case?
| ie if the SEMB port times out or has no link, reduce the port count of
| the sil3726 PMP by one.
|
| Maybe add a "enable_sil24_semb" flag to libata?
| (avoid checking unless someone asks for it). I hate magic flags but also
| don't want to subject most people to the timeout delay.
I (or Gwendal) can post a patch (and lightly test) for any of the above.
Just need to get some guidance so we don't waste our time.
It's not really sil24 tho. But anyways, I think we can just disable
them altogether. It's not like they have ever worked. Just limiting
both 3726 and 4726 to 5 ports should be fine.
Sorry - You are right. I meant "enable_sil3726_semb".
I'm not sure we need to limit the SEMB ports anymore either. See below.
That said, I'm not
quite sure this is relevant to the reported problem but it's worth a
shot.
I didn't have a better idea.
I'm seeing this in sata_pmp_quirks() since ATA_LFLAG_NO_SRST was introduced:
337 static void sata_pmp_quirks(struct ata_port *ap)
338 {
339 u32 *gscr = ap->link.device->gscr;
340 u16 vendor = sata_pmp_gscr_vendor(gscr);
341 u16 devid = sata_pmp_gscr_devid(gscr);
342 struct ata_link *link;
343
344 if (vendor == 0x1095&& devid == 0x3726) {
345 /* sil3726 quirks */
346 ata_for_each_link(link, ap, EDGE) {
347 /* Class code report is unreliable and SRST
348 * times out under certain configurations.
349 */
350 if (link->pmp< 5)
351 link->flags |= ATA_LFLAG_NO_SRST |
352 ATA_LFLAG_ASSUME_ATA;
353
354 /* port 5 is for SEMB device and it
doesn't like SR ST */
355 if (link->pmp == 5)
356 link->flags |= ATA_LFLAG_NO_SRST |
357 ATA_LFLAG_ASSUME_SEMB;
358 }
But the ATA_LFLAG_NO_SRST used in line 351 is not present in the
2.6.26 tree I know works with PMPs. The original commit comment isn't
specific about exactly which HW had problems:
http://www.mail-archive.com/git-commits-head@xxxxxxxxxxxxxxx/msg24335.html
"Some links on some PMPs locks up on SRST and/or report incorrect
device signature. Implement ATA_LFLAG_NO_SRST, ASSUME_ATA and
ASSUME_SEMB to handle these quirky links. NO_SRST makes EH avoid
SRST. ASSUME_ATA and SEMB forces class code to ATA and SEMB_UNSUP
respectively. Note that SEMB isn't currently supported yet so the
_UNSUP variant is used."
Can you publish which PMP implementations sometimes lock up on SRST?
I doubt this is related to the problem Chandra is seeing but again,
don't have better ideas.
BTW, this same kernel works fine without disabling port 5 (SEMB port).
I didn't know
this until I just looked. I know previous source trees Google used
ignored SEMB port
on 3726 and I mistakenly assumed this one did too. :(
thanks,
grant
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