Re: [PATCH 3/3] arm64: dts: qcom: sm8750: Fix videocc clock inputs

[Shawn Guo <shengchao.guo@oss.qualcomm.com>]

On Fri, Sep 25, 2026 at 12:47:16PM +0300, Abel Vesa wrote:
> On 26-09-25 00:11:52, Shawn Guo wrote:
> > The videocc node passes GCC_VIDEO_AHB_CLK as its second input and stops
> > there. videocc-sm8750.c declares its DT inputs as DT_BI_TCXO,
> > DT_BI_TCXO_AO and DT_SLEEP_CLK, so the second input is the always-on
> > board XO rather than an AHB clock, and the sleep clock is missing
> > entirely.
> > 
> > The missing third input leaves video_cc_sleep_clk_src unable to resolve
> > its parent, so it registers as an orphan clock and cannot be rated.
> > The AHB phandle in the always-on XO slot is not resolved by the driver
> > today, but it implies a parent relationship the hardware does not have.
> > 
> > Pass bi_tcxo_ao_div2 and the board sleep clock instead.
> 
> So videocc can still function properly without the GCC video AHB clock then?

I do not have a sm8750 device to test, but I did verify the same change
on Nord, and videocc can still function properly.

Dropping gcc_video_ahb_clk as a videocc input clock shouldn't break
sm8750 videocc from what I can see.

- The AHB clock isn't a videocc input at all. The videocc clocks array is
  positional and the driver maps index 0/1/2 to
  DT_BI_TCXO/DT_BI_TCXO_AO/DT_SLEEP_CLK.

- gcc_video_ahb_clk cannot be consumed anyway. gcc_sm8750_probe() leaves
  it always enabled in probe and never registers it as a clk at all. So
  <&gcc GCC_VIDEO_AHB_CLK> resolves to nothing.

Shawn