[PATCH] drm/amd: Add the capability to mark certain firmware as "required"

[Alex Deucher]

On Wed, Dec 4, 2024 at 11:18 AM Lazar, Lijo <lijo.lazar at amd.com> wrote:
>
>
>
> On 12/4/2024 9:30 PM, Alex Deucher wrote:
> > On Wed, Dec 4, 2024 at 10:56 AM Lazar, Lijo <lijo.lazar at amd.com> wrote:
> >>
> >>
> >>
> >> On 12/4/2024 7:51 PM, Alex Deucher wrote:
> >>> On Wed, Dec 4, 2024 at 12:47 AM Lazar, Lijo <lijo.lazar at amd.com> wrote:
> >>>>
> >>>>
> >>>>
> >>>> On 12/4/2024 10:44 AM, Mario Limonciello wrote:
> >>>>>
> >>>>>>> +enum amdgpu_ucode_required {
> >>>>>>> +    AMDGPU_UCODE_NOT_REQUIRED,
> >>>>>>> +    AMDGPU_UCODE_REQUIRED,
> >>>>>>
> >>>>>> Couldn't this be handled in another API instead of having to flag every
> >>>>>> load? By default, every ucode is required and if optional may be skipped
> >>>>>> with amdgpu_ucode_request_optional() API?
> >>>>>>
> >>>>>
> >>>>> I guess this would be a smaller patch, but 6 eggs one hand, half dozen
> >>>>> in the other?
> >>>>>
> >>>>
> >>>> I thought only ISP and gpu_info (no longer there for newer SOCs) fall
> >>>> into the optional ones so far. The usage is rare, similar to the
> >>>> nowarn() API usage.
> >>>>
> >>>> Also, as far as I know, the cap microcode is a must whenever used. That
> >>>> is not optional.
> >>>>
> >>>
> >>> The cap firmware is definitely optional.  Some customers use it, some don't.
> >>>
> >>
> >> I thought optional is something that can be ignored even if FW is not
> >> found and then driver load proceeds.
> >>
> >> What is the expected driver action if we classify cap firmware as
> >> optional and then it fails on a customer system that expects it?
> >
> > I guess if the customer expects it, they can make sure it's there.
>
> I don't think customer really can do that without any diagnostic message
> from the driver. Driver has to show the right message. If it passes that
> silently and fails at some other point, it could be a totally different
> signature.

yeah, I haven't seen any bug reports about the cap firmware so the
current behavior seems to be fine.

Alex

>
> > I'm not sure how you can have both without it being optional.  For
> > customers that don't use it, requiring it would break them if it
> > wasn't present.
> >
>
> It's working so far. Having all is better as long as loading that is
> harmless.
>
> Thanks,
> Lijo
>
> > Alex
> >
> >>
> >> Thanks,
> >> Lijo
> >>
> >>
> >>> Alex
> >>>
> >>>
> >>>> Thanks,
> >>>> Lijo
> >>>>
> >>>>> Alex - what's your take?
> >>>>
> >>
>