Re: Drop 0fc6fea41c71 ("drm/i915: Disable DC states for all commits") from the 6.0.y series?

From: Greg KH
Date: Fri Aug 11 2023 - 03:16:38 EST


On Thu, Aug 10, 2023 at 01:31:00PM +0200, Thorsten Leemhuis wrote:
> On 09.08.23 11:15, Greg KH wrote:
> > On Mon, Aug 07, 2023 at 12:52:03PM +0200, Thorsten Leemhuis wrote:
> >> Hi Greg! Months ago you picked up mainline commit a2b6e99d8a6
> >> ("drm/i915: Disable DC states for all commits") for the 6.1.23 release
> >> as commit 0fc6fea41c71. It causes issues vor a few people (at least
> >> three, two of which are CCed) -- apparently because it depends on some
> >> change that wasn't picked up for 6.1.y.
>
> Fun fact: here I had an off-by-one error I noticed and fixed, but...
>
> >> This is known for a while now,
> >> but nobody has yet found which change that is (Al found something that
> >> worked for him, but that didn't work for others). For the whole story
> >> skim this ticket:
> >>
> >> https://gitlab.freedesktop.org/drm/intel/-/issues/8419
> >>
> >> I wonder if it might be better if you revert that commit for 6.0.y; I
> >> asked already in the ticket if this is likely to cause regressions for
> >> users of 6.0.y,
>
> ...here I did not. :-/ Sorry.
>
> >> but got no answer from the i915 devs (or did I miss
> >> something?). :-/
> >
> > Now reverted (note, 6.0.y is long dead, I reverted this for 6.1.y)
>
> Thx, but FWIW, seems my timing was bad. I had waited weeks before
> escalating this to you (which looking back now is something I maybe
> should have done earlier -- but first it looked like it was just one
> person/machine affected by this problem). But it seems soon after I
> brought this to your attention a solution came up, as a fix was posted
> and confirmed working by one of the reporters -- and the developer wants
> to post a backport for stable. For details see
> https://gitlab.freedesktop.org/drm/intel/-/issues/8419#note_2035731
>
> Not sure what's the right thing to do at this point for 6.1.y --
> dropping the revert maybe before you do the release? You will know best
> anyway.

Let me keep the revert, that will fix the issue now. If upstream wants
to solve this in a different/better way, we can add both patches at once
to prevent any systems from being broken.

thanks,

greg k-h