Re: [PATCH v5 5/8] clk: qcom: gcc-msm8939: mark Venus core GDSCs as hardware controlled

[Erikas Bitovtas <xerikasxx@gmail.com>]

On 5/7/26 11:59 AM, Bryan O'Donoghue wrote:
> On 07/05/2026 09:32, Erikas Bitovtas wrote:
>> Since in downstream kernel VENUS_CORE0_GDSC and VENUS_CORE1_GDSC have a
>> device tree property "qcom,supports-hw-trigger", add a HW_CTRL flag
>> to these GDSCs to indicate that they are hardware controlled.
> 
> This is a misreading/misunderstanding - supports-hw-trigger means the
> GDSC is capable of being configured this way - not that it _must_ be
> configured this way.
> 
> Which leads me back to my previous point/feedback to you in the previous
> cycle.
> 
> If you _don't_ apply this patch, do you get different behaviour when
> trying to switch on the encoder ?
> 
Running the following ffmpeg command:
ffmpeg -i Videos/big_buck_bunny_1080p_H264_AAC_25fps_7200K.mp4
-input_format h264 -c:v vp8_v4l2m2m -pix_fmt nv12
big_buck_bunny_1080p_H264_AAC_25fps_7200K.vp8.mp4

Fails with:
[vp8_v4l2m2m @ 0xffffb0386870] Using device /dev/video1
[vp8_v4l2m2m @ 0xffffb0386870] driver 'qcom-venus' on card 'Qualcomm
Venus video encoder' in mplane mode
[vp8_v4l2m2m @ 0xffffb0386870] requesting formats: output=NV12/nv12
capture=VP80/none
[mp4 @ 0xffffb4b3b7e0] Could not find tag for codec vp8 in stream #0,
codec not currently supported in container
[out#0/mp4 @ 0xffffb4265e70] Could not write header (incorrect codec
parameters ?): Invalid argument
[vf#0:0 @ 0xffffb72105b0] Error sending frames to consumers: Invalid
argument
[vf#0:0 @ 0xffffb72105b0] Task finished with error code: -22 (Invalid
argument)
[vf#0:0 @ 0xffffb72105b0] Terminating thread with return code -22
(Invalid argument)

If I revert the patch, both decoder and encoder fail. This time, encoder
fails with the following error:
[vp8_v4l2m2m @ 0xffff8d356870] Could not find a valid device
[vp8_v4l2m2m @ 0xffff8d356870] can't configure encoder
[vost#0:0/vp8_v4l2m2m @ 0xffff91b3ba80] [enc:vp8_v4l2m2m @
0xffff8eb78f40] Error while opening encoder - maybe incorrect parameters
such as bit_rate, rate, width or height.
[vf#0:0 @ 0xffff941f25b0] Error sending frames to consumers: Invalid
argument
[vf#0:0 @ 0xffff941f25b0] Task finished with error code: -22 (Invalid
argument)
[vf#0:0 @ 0xffff941f25b0] Terminating thread with return code -22
(Invalid argument)
[vost#0:0/vp8_v4l2m2m @ 0xffff91b3ba80] [enc:vp8_v4l2m2m @
0xffff8eb78f40] Could not open encoder before EOF
[vost#0:0/vp8_v4l2m2m @ 0xffff91b3ba80] Task finished with error code:
-22 (Invalid argument)
[vost#0:0/vp8_v4l2m2m @ 0xffff91b3ba80] Terminating thread with return
code -22 (Invalid argument)
[out#0/mp4 @ 0xffff91265e70] Nothing was written into output file,
because at least one of its streams received no packets.
>> Venus core clock cannot be enabled if Venus core GDSCs are switched off.
> 
> True.
> 
>> But since they are hardware controlled
> 
> False. Your patch makes it so.
> 
> The question is, is that change actually required and/or beneficial here ?
> 
>  they can be switched off at
>> any moment. Vote for the Venus core clock to enable it later when GDSCs
>> get turned on.