| Message ID | 20240125-dispcc-sm8550-sm8650-drop-disp-ahb-clk-v1-0-0f8d96156156@linaro.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | clk: qcom: sm8[56]50: Drop the Disp AHB clock from Display Clock Controller | expand |
On 1/25/24 10:27, Abel Vesa wrote: > The Disp AHB clock is provided by the GCC but never registered. It is > instead enabled on probe as it is expected to be always-on. So it should > be dropped from Disp CC entirely. > > Signed-off-by: Abel Vesa <abel.vesa@linaro.org> > --- Abel, you just raised some concerns over my series doing this and now you're doing the same, plus breaking backwards compatibility for no good reason, instead of solving the problem. The correct solution here is to register the AHB clock with GCC and pm_clk_add() it from dispcc's .probe (and enable runtime PM on dispcc if it's already not the case). Then the AHB clock will be gated when no display hardware (= no dispcc consumer) is in use. 8[56]50 are in a good position for this, as they already have the required DTS reference. Unfortunately, I still haven't fully dug into this for platforms without one, but that's on me. Konrad
On 24-01-25 10:49:23, Konrad Dybcio wrote: > > > On 1/25/24 10:27, Abel Vesa wrote: > > The Disp AHB clock is provided by the GCC but never registered. It is > > instead enabled on probe as it is expected to be always-on. So it should > > be dropped from Disp CC entirely. > > > > Signed-off-by: Abel Vesa <abel.vesa@linaro.org> > > --- > > Abel, you just raised some concerns over my series doing this and now > you're doing the same, plus breaking backwards compatibility for no > good reason, instead of solving the problem. Sorry but, during the off-list discussion, you convinced me that it is OK to drop their registration as long as we enable them on probe. I've not seen the following reply in time before sending current series: https://lore.kernel.org/all/6aa58497-9727-4601-b6eb-264c478997c3@linaro.org/ Since this is blocking the patches for dispcc and dts for X1E80100, I thought I'd just drop the clock as required from DT point of view. But yeah, you're right, it breaks bindings ABI and that's wrong. > > The correct solution here is to register the AHB clock with GCC and > pm_clk_add() it from dispcc's .probe (and enable runtime PM on dispcc > if it's already not the case). Then the AHB clock will be gated when > no display hardware (= no dispcc consumer) is in use. I agree. > > 8[56]50 are in a good position for this, as they already have the > required DTS reference. Unfortunately, I still haven't fully dug > into this for platforms without one, but that's on me. Since I need to do this for the X1E80100, I'll probably do it for the other two as well. Sorry for the misunderstanding. > > Konrad
On 1/25/24 11:44, Abel Vesa wrote: > On 24-01-25 10:49:23, Konrad Dybcio wrote: >> >> >> On 1/25/24 10:27, Abel Vesa wrote: >>> The Disp AHB clock is provided by the GCC but never registered. It is >>> instead enabled on probe as it is expected to be always-on. So it should >>> be dropped from Disp CC entirely. >>> >>> Signed-off-by: Abel Vesa <abel.vesa@linaro.org> >>> --- >> >> Abel, you just raised some concerns over my series doing this and now >> you're doing the same, plus breaking backwards compatibility for no >> good reason, instead of solving the problem. > > Sorry but, during the off-list discussion, you convinced me that it is OK to drop > their registration as long as we enable them on probe. > > I've not seen the following reply in time before sending current series: > https://lore.kernel.org/all/6aa58497-9727-4601-b6eb-264c478997c3@linaro.org/ > > Since this is blocking the patches for dispcc and dts for X1E80100, I > thought I'd just drop the clock as required from DT point of view. > But yeah, you're right, it breaks bindings ABI and that's wrong. > >> >> The correct solution here is to register the AHB clock with GCC and >> pm_clk_add() it from dispcc's .probe (and enable runtime PM on dispcc >> if it's already not the case). Then the AHB clock will be gated when >> no display hardware (= no dispcc consumer) is in use. > > I agree. > >> >> 8[56]50 are in a good position for this, as they already have the >> required DTS reference. Unfortunately, I still haven't fully dug >> into this for platforms without one, but that's on me. > > Since I need to do this for the X1E80100, I'll probably do it for the > other two as well. Thanks! > > Sorry for the misunderstanding. The story is confusing as per usual, perhaps I could have explained it better in the first place.. Konrad
The Disp AHB clock is provided by the GCC but never registered. It is instead enabled on probe as it is expected to be always-on. So it should be dropped from Disp CC entirely. Signed-off-by: Abel Vesa <abel.vesa@linaro.org> --- Abel Vesa (5): dt-bindings: clock: sm8550-dispcc: Drop the Disp AHB clock arm64: dts: qcom: sm8550: Drop the Disp AHB clock from dispcc node arm64: dts: qcom: sm8650: Drop the Disp AHB clock from dispcc node clk: qcom: dispcc-sm8550: Drop the Disp AHB DT provided clock clk: qcom: dispcc-sm8650: Drop the Disp AHB DT provided clock Documentation/devicetree/bindings/clock/qcom,sm8550-dispcc.yaml | 2 -- arch/arm64/boot/dts/qcom/sm8550.dtsi | 1 - arch/arm64/boot/dts/qcom/sm8650.dtsi | 1 - drivers/clk/qcom/dispcc-sm8550.c | 1 - drivers/clk/qcom/dispcc-sm8650.c | 1 - 5 files changed, 6 deletions(-) --- base-commit: 01af33cc9894b4489fb68fa35c40e9fe85df63dc change-id: 20240125-dispcc-sm8550-sm8650-drop-disp-ahb-clk-fa011f7be9fa Best regards,