Re: [RFC WIP PATCH] venus: add qcom,no-low-power property

On 20/02/2024 12:37, Krzysztof Kozlowski wrote:

On 20/02/2024 12:21, Bryan O'Donoghue wrote:

quoted

On 20/02/2024 10:56 a.m., Marc Gonzalez wrote:

quoted

On 19/02/2024 20:24, Bryan O'Donoghue wrote:

quoted

On 19/02/2024 5:44 p.m., Dmitry Baryshkov wrote:

quoted

On Mon, 19 Feb 2024 at 19:29, Konrad Dybcio wrote:

quoted

On 19.02.2024 18:18, Marc Gonzalez wrote:

quoted

On our msm8998-based device, calling venus_sys_set_power_control()
breaks playback. Since the vendor kernel never calls it, we assume
it should not be called for this device/FW combo.

FWIW, this is also broken on other SoCs.. 8280/8350 and 6115
to name a couple.

Then let's just disable it until it gets unbroken?

Its functional on most of our upstream stuff though, why switch if off
unless necessary ?

Maybe it should be an opt-in instead of an opt-out, TBH my own feeling
is its better to minimize the amount of work and opt as per the proposed
patch.

Perhaps the qcom vidc team can give insights on 8280xp and 8350 when we
come to tackling new HFI6XX and later SoCs ...

I was wondering if the chosen property name might cause issues later...

Thinking "qcom,no-low-power" might be a bit too general?
Perhaps would need to mention venus somewhere in the name,
to limit this to the video decoder?

Yep, the word venus should probably appear in the property name.

This is RFC, so I am ignoring it, but just in case before you send v2
with the same:

You described the desired Linux feature or behavior, not the actual
hardware. The bindings are about the latter, so instead you need to
rephrase the property and its description to match actual hardware
capabilities/features/configuration etc.

I added the RFC tag explicitly because I was hoping for the DT folks
and msm maintainers to comment on the property name ;)

Thanks for your comment!

Here's the proposal for v2:

qcom,venus-broken-low-power-mode

Description:
This property is defined for devices where playback does not work
when the video decoder is in low power mode.

Regards