[Intel-gfx] Correct DMC version for Skylake (1.23 vs 1.26)

[Rodrigo Vivi]

On Tue, Aug 9, 2016 at 1:48 AM, Jani Nikula <jani.nikula at linux.intel.com> wrote:
> On Tue, 09 Aug 2016, Daniel Klaffenbach <danielklaffenbach at gmail.com> wrote:
>> Hi,
>>
>> which one is the correct DMC version to load for Linux 4.8-rc1? The
>> binary blob in linux-firmware.git is v1.26, which is also the latest
>> version available for download at the linuxgraphics website.
>>
>> Version 1.26 used to load just fine on Kernels 4.6 and 4.7. Commit
>> 4aa7fb9c introduced version pinning for v1.26 (both in
>> drm-intel-nightly and the current for-linux-next branch). Later an
>> older commit was pushed (a4a027a8), which lowered the
>> required DMC firmware to v1.23 again, without removing the
>> pinning.
>>
>> Now the situation is that v1.23 is pinned ATM, but v1.26 has been
>> released through linux-firmware.git and is being rolled out to end
>> users right now.
>>
>> What to do now? Is this a bug or a feature?

It is a bug, I'm sending a patch right now.

>
> You should use whichever version the kernel asks. The bug is that v1.23
> was dropped from linux-firmware.

1.23 was intentionally dropped from linux-firmware since 1.26 was
already the required one by our driver.

Some merge probably failed and overwrote what Patrik had properly done
in commit  4aa7fb9c ("drm/i915/dmc: Step away from symbolic
links")

> We may later upgrade the firmware the
> kernel asks, and even backport said upgrade to stable kernels after
> ensuring it works.
>
> Rodrigo, please fix linux-firmware.

No, I'm going to fix our driver.

Well, I can restore the 1.23 there if you tell me there is no way we
can make sure this patch that I'm about to send will land and be
backported on time, but this is not the ideal since we know 1.23 will
cause bugs.

Thanks,
Rodrigo

>
> BR,
> Jani.
>
>>
>>
>> Regards,
>>  Dan
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Jani Nikula, Intel Open Source Technology Center



-- 
Rodrigo Vivi
Blog: http://blog.vivi.eng.br