Re: drm/amd/display: Pass pwrseq inst for backlight and ABM

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Dec 02, 2024 at 12:33:48PM +0100, Christoph Biedl wrote:
> Alex Deucher wrote... [ back in January ]
> 
> > Please cherry pick upstream commit b17ef04bf3a4 ("drm/amd/display:
> > Pass pwrseq inst for backlight and ABM") to stable kernel 6.6.x and
> > newer.
> >
> > This fixes broken backlight adjustment on some AMD platforms with eDP panels.
> 
> Hello,
> 
> tl;dr: Was it possible to have this in 6.1.y?
> 
> after a lenghty bisect session it seems[1] this commit b17ef04bf3a4
> ("drm/amd/display: Pass pwrseq inst for backlight and ABM") indeed
> fixes an issue with a HP mt645[2]: Without it, the backlight stays at
> full brightness all the time, writing various values to the usual sysfs
> place has no effect.
> 
> That commit was backported to 6.6.y (as 71be0f674070) but not to 6.1.y -
> which is the series where I'd like to see that issue fixed. However, is
> does not apply, lot of failed hunks and missing files. So I was
> wondering whether it had been skipped deliberately because a backport
> was deemed impossible - or whether it might be doable with some
> more-than-usual effort. In the latter case, I might be willing to do the
> task, but quite frankly, lacking any understanding of what the code
> does, I'd only try to resolve the conflicts and check whether things
> work.
> 
> So I'd be glad if you could give me some insight here: Would it be worth
> the efforts trying to bring this to 6.1.y?

Why not just move to 6.6.y instead?  What's preventing that from
happening?

thanks,

greg k-h