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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Ondrej Jirman <megous@megous.com>,
	Sasha Levin <sashal@kernel.org>,
	Maxime Ripard <maxime@cerno.tech>,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org
Subject: [PATCH AUTOSEL 5.8 23/72] arm64: dts: sun50i-pinephone: dldo4 must not be >= 1.8V
Date: Sat,  8 Aug 2020 19:34:52 -0400	[thread overview]
Message-ID: <20200808233542.3617339-23-sashal@kernel.org> (raw)
In-Reply-To: <20200808233542.3617339-1-sashal@kernel.org>

From: Ondrej Jirman <megous@megous.com>

[ Upstream commit 86be5c789690eb08656b08c072c50a7b02bf41f1 ]

Some outputs from the RTL8723CS are connected to the PL port (BT_WAKE_AP),
which runs at 1.8V. When BT_WAKE_AP is high, the PL pin this signal is
connected to is overdriven, and the whole PL port's voltage rises
somewhat. This results in changing voltage on the R_PWM pin (PL10),
which is the cause for backlight flickering very noticeably when typing
on a Bluetooth keyboard, because backlight intensity is highly sensitive
to the voltage of the R_PWM pin.

Limit the maximum WiFi/BT I/O voltage to 1.8V to avoid overdriving
the PL port pins via BT and WiFi IO port signals. WiFi and BT
functionality is unaffected by this change.

This completely stops the backlight flicker when using bluetooth.

Fixes: 91f480d40942 ("arm64: dts: allwinner: Add initial support for Pine64 PinePhone")
Signed-off-by: Ondrej Jirman <megous@megous.com>
Link: https://lore.kernel.org/r/20200703194842.111845-4-megous@megous.com
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
index cefda145c3c9d..342733a20c337 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
@@ -279,7 +279,7 @@ &reg_dldo3 {
 
 &reg_dldo4 {
 	regulator-min-microvolt = <1800000>;
-	regulator-max-microvolt = <3300000>;
+	regulator-max-microvolt = <1800000>;
 	regulator-name = "vcc-wifi-io";
 };
 
-- 
2.25.1


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  parent reply	other threads:[~2020-08-08 23:39 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-08 23:34 [PATCH AUTOSEL 5.8 01/72] ARM: dts: stm32: fix uart nodes ordering in stm32mp15-pinctrl Sasha Levin
2020-08-08 23:34 ` [PATCH AUTOSEL 5.8 02/72] ARM: dts: stm32: fix uart7_pins_a comments " Sasha Levin
2020-08-08 23:34 ` [PATCH AUTOSEL 5.8 10/72] arm64: dts: rockchip: fix rk3368-lion gmac reset gpio Sasha Levin
2020-08-08 23:34 ` [PATCH AUTOSEL 5.8 11/72] arm64: dts: rockchip: fix rk3399-puma vcc5v0-host gpio Sasha Levin
2020-08-08 23:34 ` [PATCH AUTOSEL 5.8 12/72] arm64: dts: rockchip: fix rk3399-puma gmac reset gpio Sasha Levin
2020-08-08 23:34 ` [PATCH AUTOSEL 5.8 20/72] ARM: exynos: MCPM: Restore big.LITTLE cpuidle support Sasha Levin
2020-08-08 23:34 ` [PATCH AUTOSEL 5.8 22/72] firmware: arm_scmi: Fix SCMI genpd domain probing Sasha Levin
2020-08-08 23:34 ` Sasha Levin [this message]
2020-08-08 23:34 ` [PATCH AUTOSEL 5.8 24/72] arm64: dts: exynos: Fix silent hang after boot on Espresso Sasha Levin
2020-08-08 23:34 ` [PATCH AUTOSEL 5.8 27/72] clk: scmi: Fix min and max rate when registering clocks with discrete rates Sasha Levin
2020-08-08 23:35 ` [PATCH AUTOSEL 5.8 35/72] ARM: at91: pm: add missing put_device() call in at91_pm_sram_init() Sasha Levin
2020-08-08 23:35 ` [PATCH AUTOSEL 5.8 36/72] ARM: dts: exynos: Disable frequency scaling for FSYS bus on Odroid XU3 family Sasha Levin
2020-08-08 23:35 ` [PATCH AUTOSEL 5.8 38/72] ARM: dts: at91: sama5d3_xplained: change phy-mode Sasha Levin
2020-08-08 23:35 ` [PATCH AUTOSEL 5.8 39/72] ARM: dts: sunxi: bananapi-m2-plus-v1.2: Add regulator supply to all CPU cores Sasha Levin
2020-08-08 23:35 ` [PATCH AUTOSEL 5.8 40/72] ARM: dts: sunxi: bananapi-m2-plus-v1.2: Fix CPU supply voltages Sasha Levin
2020-08-08 23:35 ` [PATCH AUTOSEL 5.8 41/72] ARM: dts: stm32: Fix spi4 pins in stm32mp15-pinctrl Sasha Levin
2020-08-08 23:35 ` [PATCH AUTOSEL 5.8 49/72] arm64: dts: meson: misc fixups for w400 dtsi Sasha Levin
2020-08-08 23:35 ` [PATCH AUTOSEL 5.8 50/72] arm64: dts: meson: fix mmc0 tuning error on Khadas VIM3 Sasha Levin
2020-08-08 23:35 ` [PATCH AUTOSEL 5.8 52/72] spi: rockchip: Fix error in SPI slave pio read Sasha Levin
2020-08-08 23:35 ` [PATCH AUTOSEL 5.8 53/72] ARM: socfpga: PM: add missing put_device() call in socfpga_setup_ocram_self_refresh() Sasha Levin
2020-08-08 23:35 ` [PATCH AUTOSEL 5.8 56/72] irqchip/ti-sci-inta: Fix return value about devm_ioremap_resource() Sasha Levin

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