I wrote:
>   I have an issue with suspend to RAM and I/O load on a disk. Symptoms
> are that the disk does not respond to requests when woken up, producing
> only I/O errors on all tested kernels (newest 2.6.35-rc4 (Ubuntu
> mainline PPA build)):
> 
<snip>
 
> This can be triggered most reliably with multiple "direct" writes to
> disk, I create the load with the attached script. If the issue is
> triggered, suspend (through pm-suspend) takes very long.

Attached now...

> IMHO the interesting log output during suspend is:
> [ 1674.700125] ata1.00: qc timeout (cmd 0xec)

Almighty google suggested to try "pci=nomsi", which seems to have
cured the issue for me for now. Is that plausible? I'll keep this
under observation.

Thanks,
  Stephan