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

[Mario Limonciello]

On 12/4/2024 10:00, 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'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.
> 

Besides those, there were a few others I marked as optional too.  We 
have a few cases that we do a "fallback" firmware.  If that one isn't 
found try to get another filename.

I marked the first one as optional and the fallback one as required.
So effectively if both are missing they'll get exactly one message in 
the logs about missing firmware.

> Alex
> 
>>
>> Thanks,
>> Lijo
>>
>>
>>> Alex
>>>
>>>
>>>> Thanks,
>>>> Lijo
>>>>
>>>>> Alex - what's your take?
>>>>
>>