Re: [PATCH 2/2] media: iris: Enable Gen2 HFI on SC7280

[Konrad Dybcio]

On 2/12/26 2:27 PM, Bryan O'Donoghue wrote:
> On 12/02/2026 13:05, Dikshita Agarwal wrote:
>>
>>
>> On 2/12/2026 5:13 PM, Konrad Dybcio wrote:
>>> On 2/12/26 12:16 PM, Dikshita Agarwal wrote:
>>>>
>>>>
>>>> On 2/9/2026 6:05 PM, Dmitry Baryshkov wrote:
>>>>> On Mon, Feb 09, 2026 at 05:04:48PM +0530, Dikshita Agarwal wrote:
>>>>>>
>>>>>>
>>>>>> On 2/9/2026 3:32 PM, Konrad Dybcio wrote:
>>>>>>> On 2/9/26 10:45 AM, Dikshita Agarwal wrote:
>>>>>>>> SC7280 supports both Gen1 and Gen2 HFI firmware. The driver continues to
>>>>>>>> use Gen1 by default, but boards that intend to use Gen2 firmware can
>>>>>>>> opt‑in by specifying a Gen2 image through the Device Tree
>>>>>>>> 'firmware-name' property.
>>>>>>>>
>>>>>>>> Based on this property and the availability of the referenced
>>>>>>>> firmware binary, the driver selects the appropriate HFI generation and
>>>>>>>> updates its platform data accordingly. Boards that do not
>>>>>>>> specify a Gen2 firmware, or where the firmware is not present,
>>>>>>>> automatically fall back to Gen1.
>>>>>>>>
>>>>>>>> Signed-off-by: Dikshita Agarwal <dikshita.agarwal@xxxxxxxxxxxxxxxx>
>>>>>>>> ---
>>>
>>> [...]
>>>
>>>>>> To avoid accidental matches, I can switch to an exact filename match
>>>>>> instead. That way, only the specific Gen2 image (for example
>>>>>> "qcom/vpu/vpu20_p1_gen2.mbn") will trigger the Gen2 path, and boards that
>>>>>
>>>>> How do you detect that for the OEM-signed firmware, which can have
>>>>> random name?
>>>>>
>>>>>> want to use Gen2 can opt in by naming the firmware accordingly.
>>>>
>>>> I Explored on suggested alternative approaches and seeing some limitation
>>>> with the both of them:
>>>>
>>>> 1. Detecting Gen1/Gen2 by scanning the firmware blob (fw->data)
>>>> It is possible to parse QC_IMAGE_VERSION_STRING from the .mbn and  extract
>>>> the version string. The issues with this approach :
>>>>
>>>> - the version string has no explicit marker that identifies Gen1 vs Gen2.
>>>>
>>>> - This prefix is not a formal ABI, and it is not consistent across SoCs.
>>>> Each SoC family uses different naming patterns in the version string.
>>>>
>>>> Example : For SC7280 Gen1 we currently see:
>>>> QC_IMAGE_VERSION_STRING=video-firmware.1.0-<hash> while SM8250 has
>>>> QC_IMAGE_VERSION_STRING=VIDEO.VPU.1.0-00119-<>
>>>>
>>>> So the driver would need SoC‑specific string‑matching rules, which is hard
>>>> to maintain if we are looking for a design to address all available SOCs.
>>>
>>> The only SoC with such distinction today is kodiak. So we can simply check:
>>>
>>> if (kodiak && strstr(fw->data, "VIDEO.VPU.1.0.")
>>>     hfi = gen2;
>>
>> Agree, this works for Kodiak. However, Dmitry was also referring to other
>> SoCs that may support both Gen1 and Gen2, and at the moment there isn’t a
>> generic way to handle that check.
>>
>> Also, please note that the Kodiak Gen1 firmware uses the string
>> video-firmware.1.0, whereas Gen2 uses VIDEO.VPU.3.4.
>>
>>>
>>>
>>> Can we agree that VIDEO.VPU.x firmwares are hfigen2? If so, problem also
>>> solved for <=8450
>>>
>>
>> Nope. that's not true for all, SM8250 uses VIDEO.VPU.1.0 which is gen1.
>>
>> Thanks,
>> Dikshita
>>
>>> Konrad
> 
> I really don't see what the problem with Dikshita's proposal here is after all she literally controls the firmware name that goes to linux-firmware.

A vendor could name their gen1 binary i_really_wanted_gen2_but_didnt_get_it.mbn,
or perhaps "snapdragon_8_gen_2_venus.mbn" and we can't control it.

Plus I generally see relying on file*names* as a hack (in the same way that
Linux doesn't care about file extensions, but Windows blindly trusts them).
And there's oddball cases like with FW_LOADER_USER_HELPER

Konrad