[PATCH] Revert "drm/nouveau/fifo/gk104: kick channels when deactivating them"

[Alexandre Courbot]

On Wed, Aug 12, 2015 at 3:00 PM, Afzal Mohammed <afzal.mohd.ma at gmail.com> wrote:
> Hi,
>
> On Wed, Aug 12, 2015 at 01:17:38PM +0900, Alexandre Courbot wrote:
>> This reverts commit 1addc1264852
>>
>> This commit seems to cause crashes in gk104_fifo_intr_runlist() by
>> returning 0xbad0da00 when register 0x2a00 is read. Since this commit was
>> intended for GM20B which is not completely supported yet, let's revert
>> it for the time being.
>>
>> Reported-by: Eric Biggers <ebiggers3 at gmail.com>
>> Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
>> ---
>> David, it would be great if this could be merged for 4.2 since lots of
>> users could potentially experience this issue. Thanks!
>
> Tested-by: Afzal Mohammed <afzal.mohd.ma at gmail.com>

Thanks!

>
> Please help $subject reach mainline for 4.2, w/o this revert, the
> system here hangs most (>90%) of the time at boot time.
>
> As an aside, yesterday after a marathon git bisect, came to the same
> solution (though I don't understand what that change means). Was
> about to report it and saw this one. Thanks Alexandre.

All credit goes to Eric for bisecting and reporting this issue.

>
> W/o the revert, in the rare case where it boots, below is observed in
> addition to as compared to w/ revert,
>
> [    9.826010] nouveau E[    PBUS][0000:01:00.0] MMIO read of 0x00000000 FAULT at 0x122130 [ !ENGINE ]

Could you let me know what your card is? It may be useful to know the
range of affected cards when trying to fix this.

Thanks,
Alex.