Re: [RFT PATCH] arm64: dts: sdm845: Add iommus property to qup

[Vinod Koul <vkoul@kernel.org>]

Hi Bjorn, Steve,

On 20-10-20, 08:03, Bjorn Andersson wrote:
> From: Stephen Boyd <swboyd@chromium.org>
> 
> The SMMU that sits in front of the QUP needs to be programmed properly
> so that the i2c geni driver can allocate DMA descriptors. Failure to do
> this leads to faults when using devices such as an i2c touchscreen where
> the transaction is larger than 32 bytes and we use a DMA buffer.

So I tried this and results in reboot for me when I use it in GSI
driver in RB3. I seem to already have the iommu properties [1] but values
are different

[1]: https://git.linaro.org/people/vinod.koul/kernel.git/commit/?h=topic/gsi3-db&id=385edef08d55432a40fc9a8ae1f49248d5417a92

> arm-smmu 15000000.iommu: Unexpected global fault, this could be serious
> arm-smmu 15000000.iommu:         GFSR 0x00000002, GFSYNR0 0x00000002, GFSYNR1 0x000006c0, GFSYNR2 0x00000000
> 
> Add the right SID and mask so this works.
> 
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> [bjorn: Define for second QUP as well]
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>  arch/arm64/boot/dts/qcom/sdm845.dtsi | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> index 8eb5a31346d2..7d635bc919cb 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> @@ -811,6 +811,7 @@ qupv3_id_0: geniqup@8c0000 {
>  			clock-names = "m-ahb", "s-ahb";
>  			clocks = <&gcc GCC_QUPV3_WRAP_0_M_AHB_CLK>,
>  				 <&gcc GCC_QUPV3_WRAP_0_S_AHB_CLK>;
> +			iommus = <&apps_smmu 0x0 0x3>;
>  			#address-cells = <2>;
>  			#size-cells = <2>;
>  			ranges;
> @@ -1119,6 +1120,7 @@ qupv3_id_1: geniqup@ac0000 {
>  			clock-names = "m-ahb", "s-ahb";
>  			clocks = <&gcc GCC_QUPV3_WRAP_1_M_AHB_CLK>,
>  				 <&gcc GCC_QUPV3_WRAP_1_S_AHB_CLK>;
> +			iommus = <&apps_smmu 0x6c0 0x3>;
>  			#address-cells = <2>;
>  			#size-cells = <2>;
>  			ranges;
> -- 
> 2.28.0

-- 
~Vinod