On 03/06/2025 21:43, Michal Wilczynski wrote:
>>> + * and resets. Otherwise, we fall back to managing them ourselves.
>>> + */
>>> + pvr_dev->pwrseq = devm_pwrseq_get(dev, "gpu-power");
>>> + if (IS_ERR(pvr_dev->pwrseq)) {
>>> + int pwrseq_err = PTR_ERR(pvr_dev->pwrseq);
>>> +
>>> + /*
>>> + * If the error is -EPROBE_DEFER, it's because the
>>> + * optional sequencer provider is not present
>>> + * and it's safe to fall back on manual power-up.
>>
>> It is safe but why it is desirable? The rule is rather to defer the
>> probe, assuming this is probe path.
>
> Yeah this is probe path.
>
> The GPU node will depend on the AON node, which will be the sole
> provider for the 'gpu-power' sequencer (based on the discussion in patch
> 1).
>
> Therefore, if the AON/pwrseq driver has already completed its probe, and
> devm_pwrseq_get() in the GPU driver subsequently returns -EPROBE_DEFER
> (because pwrseq_get found 'no match' on the bus for 'gpu-power'), the
> interpretation is that the AON driver did not register this optional
> sequencer. Since AON is the only anticipated source, it implies the
> sequencer won't become available later from its designated provider.
I don't understand why you made this assumption. AON could be a module
and this driver built-in. AON will likely probe later.
Best regards,
Krzysztof
