6.10-stable review patch. If anyone has any objections, please let me know.
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From: Pin-yen Lin treapking@chromium.org
[ Upstream commit 897a7edba9330974726c564dfdbf4fb5e203b9ac ]
Set off-on-delay-us to 500000 us for pp3300_mipibrdg to make sure it complies with the panel's unprepare delay (the time to power down completely) of the power sequence. Explicit configuration on the regulator node is required because mt8192-asurada uses the same power supply for the panel and the anx7625 DP bridge.
For example, the power sequence could be violated in this sequence: 1. Bridge on: panel goes off, but regulator doesn't turn off (refcount=1). 2. Bridge off: regulator turns off (refcount=0). 3. Bridge resume -> regulator turns on but the bridge driver doesn't check the delay.
Or in this sequence: 1. Bridge on: panel goes off. The regulator doesn't turn off (refcount=1), but the .unprepared_time in panel_edp is still updated. 2. Bridge off, regulator goes off (refcount=0). 3. Panel on, but the panel driver uses the wrong .unprepared_time to check the unprepare delay.
Fixes: f9f00b1f6b9b ("arm64: dts: mediatek: asurada: Add display regulators") Signed-off-by: Pin-yen Lin treapking@chromium.org Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Link: https://lore.kernel.org/r/20240502154455.3427793-1-treapking@chromium.org Signed-off-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi b/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi index 7a704246678f0..08d71ddf36683 100644 --- a/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi +++ b/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi @@ -147,6 +147,7 @@ pp3300_mipibrdg: regulator-3v3-mipibrdg { regulator-boot-on; gpio = <&pio 127 GPIO_ACTIVE_HIGH>; vin-supply = <&pp3300_g>; + off-on-delay-us = <500000>; };
/* separately switched 3.3V power rail */