Re: [PATCH] drm/msm/dp: add module parameter for PSR

[Johan Hovold]

On Wed, May 24, 2023 at 11:06:03AM +0300, Dmitry Baryshkov wrote:
> On 24/05/2023 09:59, Johan Hovold wrote:

> > Regressions happen and sometimes there are corner cases that are harder
> > to find, but this is a breakage of a fundamental feature that was
> > reported before the code was even merged into mainline.
> > 
> >> We should have ideally gone with the modparam with the feature patches
> >> itself knowing that it gets enabled for all sinks if PSR is supported.
> > 
> > Modparams are things of the past should not be used to enable broken
> > features so that some vendor can tick of their internal lists of
> > features that have been "mainlined".
> 
> We have had a history of using modparam with i915 and IIRC amdgpu / 
> radeon drivers to allow users to easily check whether new feature works 
> for their hardware. My current understanding is that PSR+VT works for on 
> some laptops and doesn't on some other laptops, which makes it a valid case.

But here it does not seem to be the hardware that's the issue, but
rather that the implementation is incorrect or incomplete.

Johan