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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
	devicetree@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
	Krzysztof Kozlowski <krzk@kernel.org>,
	Willy Wolff <willy.mh.wolff.ml@gmail.com>,
	linux-arm-kernel@lists.infradead.org,
	Marek Szyprowski <m.szyprowski@samsung.com>
Subject: [PATCH AUTOSEL 5.7 33/58] ARM: dts: exynos: Disable frequency scaling for FSYS bus on Odroid XU3 family
Date: Sat,  8 Aug 2020 19:36:59 -0400	[thread overview]
Message-ID: <20200808233724.3618168-33-sashal@kernel.org> (raw)
In-Reply-To: <20200808233724.3618168-1-sashal@kernel.org>

From: Marek Szyprowski <m.szyprowski@samsung.com>

[ Upstream commit 9ff416cf45a08f28167b75045222c762a0347930 ]

Commit 1019fe2c7280 ("ARM: dts: exynos: Adjust bus related OPPs to the
values correct for Exynos5422 Odroids") changed the parameters of the
OPPs for the FSYS bus. Besides the frequency adjustments, it also removed
the 'shared-opp' property from the OPP table used for FSYS_APB and FSYS
busses.

This revealed that in fact the FSYS bus frequency scaling never worked.
When one OPP table is marked as 'opp-shared', only the first bus which
selects the OPP sets the rate of its clock. Then OPP core assumes that
the other busses have been changed to that OPP and no change to their
clock rates are needed. Thus when FSYS_APB bus, which was registered
first, set the rate for its clock, the OPP core did not change the FSYS
bus clock later.

The mentioned commit removed that behavior, what introduced a regression
on some Odroid XU3 boards. Frequency scaling of the FSYS bus causes
instability of the USB host operation, what can be observed as network
hangs. To restore old behavior, simply disable frequency scaling for the
FSYS bus.

Reported-by: Willy Wolff <willy.mh.wolff.ml@gmail.com>
Fixes: 1019fe2c7280 ("ARM: dts: exynos: Adjust bus related OPPs to the values correct for Exynos5422 Odroids")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/boot/dts/exynos5422-odroid-core.dtsi | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/arm/boot/dts/exynos5422-odroid-core.dtsi b/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
index ab27ff8bc3dca..afe090578e8fa 100644
--- a/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
+++ b/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
@@ -411,12 +411,6 @@ &bus_fsys_apb {
 	status = "okay";
 };
 
-&bus_fsys {
-	operating-points-v2 = <&bus_fsys2_opp_table>;
-	devfreq = <&bus_wcore>;
-	status = "okay";
-};
-
 &bus_fsys2 {
 	operating-points-v2 = <&bus_fsys2_opp_table>;
 	devfreq = <&bus_wcore>;
-- 
2.25.1


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  parent reply	other threads:[~2020-08-08 23:47 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-08 23:36 [PATCH AUTOSEL 5.7 01/58] ARM: dts: stm32: fix uart7_pins_a comments in stm32mp15-pinctrl Sasha Levin
2020-08-08 23:36 ` [PATCH AUTOSEL 5.7 08/58] arm64: dts: rockchip: fix rk3368-lion gmac reset gpio Sasha Levin
2020-08-08 23:36 ` [PATCH AUTOSEL 5.7 09/58] arm64: dts: rockchip: fix rk3399-puma vcc5v0-host gpio Sasha Levin
2020-08-08 23:36 ` [PATCH AUTOSEL 5.7 10/58] arm64: dts: rockchip: fix rk3399-puma gmac reset gpio Sasha Levin
2020-08-08 23:36 ` [PATCH AUTOSEL 5.7 17/58] ARM: exynos: MCPM: Restore big.LITTLE cpuidle support Sasha Levin
2020-08-08 23:36 ` [PATCH AUTOSEL 5.7 19/58] firmware: arm_scmi: Fix SCMI genpd domain probing Sasha Levin
2020-08-08 23:36 ` [PATCH AUTOSEL 5.7 20/58] arm64: dts: sun50i-pinephone: dldo4 must not be >= 1.8V Sasha Levin
2020-08-08 23:36 ` [PATCH AUTOSEL 5.7 21/58] arm64: dts: exynos: Fix silent hang after boot on Espresso Sasha Levin
2020-08-08 23:36 ` [PATCH AUTOSEL 5.7 24/58] clk: scmi: Fix min and max rate when registering clocks with discrete rates Sasha Levin
2020-08-08 23:36 ` [PATCH AUTOSEL 5.7 32/58] ARM: at91: pm: add missing put_device() call in at91_pm_sram_init() Sasha Levin
2020-08-08 23:36 ` Sasha Levin [this message]
2020-08-08 23:37 ` [PATCH AUTOSEL 5.7 35/58] ARM: dts: sunxi: bananapi-m2-plus-v1.2: Add regulator supply to all CPU cores Sasha Levin
2020-08-08 23:37 ` [PATCH AUTOSEL 5.7 36/58] ARM: dts: sunxi: bananapi-m2-plus-v1.2: Fix CPU supply voltages Sasha Levin
2020-08-08 23:37 ` [PATCH AUTOSEL 5.7 42/58] arm64: dts: meson: fix mmc0 tuning error on Khadas VIM3 Sasha Levin
2020-08-08 23:37 ` [PATCH AUTOSEL 5.7 44/58] spi: rockchip: Fix error in SPI slave pio read Sasha Levin
2020-08-08 23:37 ` [PATCH AUTOSEL 5.7 45/58] ARM: socfpga: PM: add missing put_device() call in socfpga_setup_ocram_self_refresh() Sasha Levin
2020-08-08 23:37 ` [PATCH AUTOSEL 5.7 48/58] irqchip/ti-sci-inta: Fix return value about devm_ioremap_resource() Sasha Levin

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