Re: Issue or bug concerning DRRS on old i7-4980HQ

[Jani Nikula <jani.nikula@linux.intel.com>]

On Sat, 02 Aug 2025, René Herman <rene.herman@gmail.com> wrote:
> On 01-08-2025 11:19, Jani Nikula wrote:
>
>> On Thu, 31 Jul 2025, René Herman <rene.herman@gmail.com> wrote:
>>> Here's that Ubuntu launchpad bug on freedesktop.org, but including a
>>> possibly interesting fix from 5 months ago in the currently last comment:
>>>
>>> https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/3441
>> 
>> Might be useful to attach dmesg and VBT to the bug as described at [1].
>
> Just in case: please note the freedesktop.org bug is not our bug but 
> just a 4 year old same one. I also unfortunately don't have the hardware 
> on hand, and it seems the person I am assisting with this can't due to 
> vacation get to it right now.
>
> Although I'm not a graphics/display person, seems to me it's more or 
> less fixed by Arun Murthy (added to the To: list) in the last, still 
> recent-ish comment on that bug?
>
> https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/3441#note_2803858
>
> I.e., could while working with the person with the hardware not figure 
> out what the point of that i915_drrs_ctl would be if the system 
> immediately enabled it again anyway, so Arun's approach seems to make 
> sense to me.

Hacking debugfs is not a fix, it's a hack.

> This is probably going to be a more common issue soon when these older 
> no-TPM Haswell systems get installed with Linux at the end of Windows 10 
> support.

On the upside, we'll get more people with the hardware to test.


BR,
Jani.


-- 
Jani Nikula, Intel