On Wed, Oct 09, 2019 at 08:39:26AM -0700, Stephen Boyd wrote: > Quoting Brian Masney (2019-10-08 23:05:20) > > On Tue, Oct 08, 2019 at 07:21:30PM -0700, Stephen Boyd wrote: > > > Quoting Brian Masney (2019-10-06 18:45:08) > > > > diff --git a/arch/arm/boot/dts/qcom-msm8974.dtsi b/arch/arm/boot/dts/qcom-msm8974.dtsi > > > > index 7fc23e422cc5..af02eace14e2 100644 > > > > --- a/arch/arm/boot/dts/qcom-msm8974.dtsi > > > > +++ b/arch/arm/boot/dts/qcom-msm8974.dtsi > > > > @@ -1335,6 +1342,77 @@ > > > > clocks = <&mmcc MDSS_AHB_CLK>; > > > > clock-names = "iface"; > > > > }; > > > > + > > > > + hdmi: hdmi-tx@fd922100 { > > > > + status = "disabled"; > > > > + > > > > + compatible = "qcom,hdmi-tx-8974"; > > > > + reg = <0xfd922100 0x35c>, > > > > + <0xfc4b8000 0x60f0>; > > > > + reg-names = "core_physical", > > > > + "qfprom_physical"; > > > > > > Is this the qfprom "uncorrected" physical address? If so, why can't this > > > node use an nvmem to read whatever it needs out of the qfprom? > > > > The MSM HDMI code is configured to look for this reg-name here: > > > > https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/msm/hdmi/hdmi.c#L582 > > > > There is a qcom,qfprom configured for this board in DTS, however its at > > a different address range, so maybe there are multiple qfproms? > > > > https://elixir.bootlin.com/linux/latest/source/arch/arm/boot/dts/qcom-msm8974.dtsi#L424 > > > > msm8996.dtsi has the same style of configuration: > > > > https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/qcom/msm8996.dtsi#L956 > > https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/qcom/msm8996.dtsi#L1736 > > > > There's only one qfprom and there's the address space that's > "uncorrected" which is not supposed to be used and there's the space > that is "corrected" and is supposed to be used. It looks like this is > poking the uncorrected space and it should probably stop doing that and > use the nvmem provider instead. Maybe someone with docs for this chip > and 8996 can help confirm this. Do you know of any publicly-available documentation that describes the "uncorrected" and "corrected" addresses? I got that qfprom address for the HDMI from here: https://github.com/AICP/kernel_lge_hammerhead/blob/n7.1/arch/arm/boot/dts/msm8974-mdss.dtsi#L101 I assume the downstream kernel probably doesn't have the corrected address anywhere else? Brian