Re: [3.9-rc1] irq 16: nobody cared (was [3.9-rc1] very poor interrupt responses)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, Mar 15, 2013 at 8:14 AM, Jiri Kosina <jkosina@xxxxxxx> wrote:

> Just a datapoint -- I have put a trivial debugging patch in place, and it
> reveals that "nobody cared" for irq 16 happens long after last
>
>         I915_WRITE(GMBUS4 + reg_offset, 0);
>
> has been performed in gmbus_wait_hw_status(). On the other hand, if I
> comment out both GMBUS4 register offset writes in gmbus_wait_hw_status(),
> then it of course falls back to GPIO bit-banging, but the "nobody cared"
> for irq 16 is gone.
>
> So it seems like something gets severely confused by the I915_WRITE to
> GMBUS4 + reg_offset. So far this seems to have been reported solely on
> Lenovos as far as I can see (although a completely different types), so it
> might be some platform-specific quirk?
>
> Honestly, I still don't understand how all the GMBUS stuff relates to IRQ
> 16 at all.

that device is using
i915 0000:00:02.0: irq 44 for MSI/MSI-X

so can you try to boot with pci=nomsi?
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [DMA Engine]     [Linux Coverity]     [Linux USB]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Greybus]

  Powered by Linux