Re: ata_piix resume from S3 on T43P failed

[Tejun Heo <htejun@gmail.com>]

zhao, forrest wrote:
> Hi, Tejun
> 
> We just tested your git tree on thinkpad T43P laptop, and found that
> after ata_piix resumed from S3, SATA disk can't be read/write anymore.
> But according to the test result of kernel 2.6.16-rc6 on T43P, ata_piix
> can resume from S3 successfully.
> 
> We know that this problem may be not related to your patches, but I
> think you know the libata development status very well, maybe you can
> give us some clue about what happened to ata_piix between 2.6.16-rc6 and
> your git tree.
> 

Hello, Zhao.

I haven't really followed AHCI suspend/resume stuff but AFAICT it never
made to #upstream.  I don't know whether it was included in -rc# or not.
 But it sounds like it did.

One thing to note about suspend/resume is they should be handled from
EH.  IIRC, they weren't synchronized properly with the rest of libata.
Maybe it can be another ATA_EH action or maybe it needs separate
handling but at any rate it should be handled as part of EH to be
synchronized properly.  I'm planning to work on suspend/resume once the
currently pending changes settle down.  I thought about including them
in this round but the changes were HUGE as they were, so decided to
defer it.

-- 
tejun