[Nouveau] [PATCH] drm/nouveau/bios: fix a bit shift error introduced by 457e77b

[Sergei Antonov]

On 19 April 2014 22:14, Emil Velikov <emil.l.velikov at gmail.com> wrote:
> On 15/04/14 22:49, Sergei Antonov wrote:
>> On 15 April 2014 23:18, Sergei Antonov <saproj at gmail.com> wrote:
>>> Commit 457e77b26428ab4a24998eecfb99f27fa4195397 added two checks applied to a
>>> value received from nv_rd32(bios, 0x619f04). But after this new piece of code
>>> is executed, the addr local variable does not hold the same value it used to
>>> hold before the commit. Here is what is was assigned in the original code:
>>>         (u64)(nv_rd32(bios, 0x619f04) & 0xffffff00) << 8
>>> in the committed code it ends up with this value:
>>>         (u64)(nv_rd32(bios, 0x619f04) >> 8) << 8
>>> These expressions are obviously not equivalent.
>>>
>>> My Nvidia video card does not show anything on the display when I boot a
>>> kernel containing this commit.
>>>
>>> The patch fixes the code so that the new checks are still done, but the
>>> side effect of an incorrect addr value is gone.
>>>
> Hi Sergei
>
> A similar patch [1] has been sent a few days prior to yours, and I'm assuming
> it will be queued/merged shortly. Just letting you know.
>
> Cheers
> -Emil
>
> [1] http://lists.freedesktop.org/archives/dri-devel/2014-April/057318.html

Thanks! I didn't know about this patch. Sorry for accidentally
creating a race condition.
My patch has been merged today (included in "drm fixes" from Dave Airlie).