6.6-stable review patch. If anyone has any objections, please let me know.
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From: Stephan Gerhold stephan.gerhold@linaro.org
commit f73c82c855e186e9b67125e3eee743960320e43c upstream.
On most MSM8939 devices, the bootloader already initializes the display to show the boot splash screen. In this situation, MDSS is already configured and left running when starting Linux. To avoid side effects from the bootloader configuration, the MDSS reset can be specified in the device tree to start again with a clean hardware state.
The reset for MDSS is currently missing in msm8939.dtsi, which causes errors when the MDSS driver tries to re-initialize the registers:
dsi_err_worker: status=6 dsi_err_worker: status=6 dsi_err_worker: status=6 ...
It turns out that we have always indirectly worked around this by building the MDSS driver as a module. Before v6.17, the power domain was temporarily turned off until the module was loaded, long enough to clear the register contents. In v6.17, power domains are not turned off during boot until sync_state() happens, so this is no longer working. Even before v6.17 this resulted in broken behavior, but notably only when the MDSS driver was built-in instead of a module.
Cc: stable@vger.kernel.org Fixes: 61550c6c156c ("arm64: dts: qcom: Add msm8939 SoC") Signed-off-by: Stephan Gerhold stephan.gerhold@linaro.org Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@oss.qualcomm.com Reviewed-by: Konrad Dybcio konrad.dybcio@oss.qualcomm.com Link: https://lore.kernel.org/r/20250915-msm8916-resets-v1-2-a5c705df0c45@linaro.o... Signed-off-by: Bjorn Andersson andersson@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/boot/dts/qcom/msm8939.dtsi | 2 ++ 1 file changed, 2 insertions(+)
--- a/arch/arm64/boot/dts/qcom/msm8939.dtsi +++ b/arch/arm64/boot/dts/qcom/msm8939.dtsi @@ -1210,6 +1210,8 @@
power-domains = <&gcc MDSS_GDSC>;
+ resets = <&gcc GCC_MDSS_BCR>; + #address-cells = <1>; #size-cells = <1>; #interrupt-cells = <1>;