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

["Lazar, Lijo" <lijo.lazar@amd.com>]

On 12/4/2024 10:15 PM, Alex Deucher wrote:
> On Wed, Dec 4, 2024 at 11:18 AM Lazar, Lijo <lijo.lazar@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@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@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.
> 

In this case, need to have a info level message when a firmware
classified as optional is not found. As it is only during driver load, I
don't think that message will be an annoyance. On the other hand, it
gives useful info if it runs into trouble at a later point during load.

Thanks,
Lijo

> 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?
>>>>>>
>>>>
>>