Re: MSI broken in libata?

Robert Hancock
2010-01-11T01:39:43Z

On 01/10/2010 07:15 PM, Tejun Heo wrote:
> On 01/10/2010 01:33 PM, Torsten Kaiser wrote:
>> I did try the patch from Robert Hancock in
>> http://lkml.org/lkml/2010/1/6/417 ,but without success.
>>
>> if you need any more information, or have something for me to try,
>> please just ask. I did look at the code and the documentation about
>> enabling MSI, but did not see anything (obvious) wrong, so I don't
>> know what to try next.
>
> Can you please try the attached patch?
>
> Thanks.
>

It'd be interesting to see if it makes a difference, but I don't think
the patch is quite right. According to the datasheet, doing the MSI ack
while the interrupt source is still pending will cause a new MSI to be
sent, so if you do it before handling the interrupt you'll generate a
spurious interrupt after every real one.

Though, apparently my patch that did the MSI ack after the handling
didn't help, so either that's wrong or the problem is unrelated. (I tend
to suspect the latter, given that sata_nv is also failing in the same way.)