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arm64: dts: qcom: sm8550: correct MDSS interconnects

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commit b8591df49c upstream.

SM8550 lists two interconnects for the display subsystem, mdp0-mem
(between MDP and LLCC) and mdp1-mem (between LLCC and EBI, memory).
The second interconnect is a misuse. mdpN-mem paths should be used for
several outboud MDP interconnects rather than the path between LLCC and
memory. This kind of misuse can result in bandwidth underflows, possibly
degrading picture quality as the required memory bandwidth is divided
between all mdpN-mem paths (and LLCC-EBI should not be a part of such
division).

Drop the second path and use direct MDP-EBI path for mdp0-mem until we
support separate MDP-LLCC and LLCC-EBI paths.

Fixes: d7da51db5b ("arm64: dts: qcom: sm8550: add display hardware devices")
Cc: stable@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20241026-fix-sm8x50-mdp-icc-v2-1-fd8ddf755acc@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dmitry Baryshkov
2024-10-26 20:59:40 +03:00
committed by Greg Kroah-Hartman
parent a0f741013a
commit cb86128518
1 changed files with 2 additions and 3 deletions
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arch/arm64/boot/dts/qcom/sm8550.dtsi
+2 -3
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@@ -2448,9 +2448,8 @@
power-domains = <&dispcc MDSS_GDSC>;
interconnects = <&mmss_noc MASTER_MDP 0 &gem_noc SLAVE_LLCC 0>,
<&mc_virt MASTER_LLCC 0 &mc_virt SLAVE_EBI1 0>;
interconnect-names = "mdp0-mem", "mdp1-mem";
interconnects = <&mmss_noc MASTER_MDP 0 &mc_virt SLAVE_EBI1 0>;
interconnect-names = "mdp0-mem";
iommus = <&apps_smmu 0x1c00 0x2>;