Re: [PATCH v2 3/6] arm64: dts: qcom: glymur: Add camera MCLK pinctrl

[Nihal Kumar Gupta <nihal.gupta@oss.qualcomm.com>]

On 11-11-2026 03:42, Jesse Casco wrote:
>> +			cam_mclk4_default: cam-mclk4-default-state {
>> +				pins = "gpio100";
>> +				function = "cam_asc_mclk4";
>> +				drive-strength = <2>;
>> +				bias-disable;
>> +			};
> I've been running this series on an ASUS Zenbook A16 (UX3607OA), which
> has an OV02C10 on MCLK4 at 19.2 MHz. With 2 mA here the sensor shows
> horizontal banding, and its frame period stretches by about 9%, whenever
> the internal DMIC clock (LPASS LPI GPIO6, 2.4 MHz) is running. The bands
> are already in the RAW10 frames, and the sensor test pattern is clean,
> so it looks like the MCLK pad itself rather than CSI or the ISP.
> 
> Changing only this pin to 6 mA fixes it. A/B/A across three boots, same
> kernel, fixed exposure/gain, row high-pass RMS / frame period:
> 
>   MCLK4   mic off          mic on            after
>   2 mA    0.96 / 33.28 ms  20.44 / 36.17 ms  1.04 / 33.27 ms
>   6 mA    0.89 / 33.27 ms   0.90 / 33.27 ms  0.90 / 33.27 ms
>   2 mA    0.95 / 33.27 ms  15.33 / 34.37 ms  0.93 / 33.28 ms
> 
> At 6 mA the frame timing holds steady at 33.27 ms and the image stays
> clean in every phase, including while the microphone is recording,
> which is exactly the case that couples interference into the 2 mA
> clock. Normal camera use with the mic on is also clean at 6 mA, so the
> fix holds up on real hardware, not just in the capture script.
> 
> Could cam_mclk4_default use 6 mA? If you'd rather keep 2 mA in the SoC
> dtsi, I'll override it in the A16 board DT instead.

Hi Jesse,

Thanks for the detailed testing and measurements.

Konrad, what would you suggest here: update the SoC dtsi
to 6 mA, or keep 2 mA there and override it only in the A16 board DT?

-- 
Regards,
Nihal Kumar Gupta