From 695e83a1ff2ba63aa391245c71090156b071bd1d Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Tue, 22 Sep 2020 14:40:46 +0200 Subject: [PATCH] clk: samsung: exynos4: mark 'chipid' clock as CLK_IGNORE_UNUSED [ Upstream commit f3bb0f796f5ffe32f0fbdce5b1b12eb85511158f ] The ChipID IO region has it's own clock, which is being disabled while scanning for unused clocks. It turned out that some CPU hotplug, CPU idle or even SOC firmware code depends on the reads from that area. Fix the mysterious hang caused by entering deep CPU idle state by ignoring the 'chipid' clock during unused clocks scan, as there are no direct clients for it which will keep it enabled. Fixes: e062b571777f ("clk: exynos4: register clocks using common clock framework") Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20200922124046.10496-1-m.szyprowski@samsung.com Reviewed-by: Krzysztof Kozlowski Acked-by: Sylwester Nawrocki Signed-off-by: Stephen Boyd Signed-off-by: Sasha Levin --- drivers/clk/samsung/clk-exynos4.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/clk/samsung/clk-exynos4.c b/drivers/clk/samsung/clk-exynos4.c index 6c8e45e007c84..8edbb20ccff5e 100644 --- a/drivers/clk/samsung/clk-exynos4.c +++ b/drivers/clk/samsung/clk-exynos4.c @@ -1059,7 +1059,7 @@ static struct samsung_gate_clock exynos4210_gate_clks[] __initdata = { GATE(CLK_PCIE, "pcie", "aclk133", GATE_IP_FSYS, 14, 0, 0), GATE(CLK_SMMU_PCIE, "smmu_pcie", "aclk133", GATE_IP_FSYS, 18, 0, 0), GATE(CLK_MODEMIF, "modemif", "aclk100", GATE_IP_PERIL, 28, 0, 0), - GATE(CLK_CHIPID, "chipid", "aclk100", E4210_GATE_IP_PERIR, 0, 0, 0), + GATE(CLK_CHIPID, "chipid", "aclk100", E4210_GATE_IP_PERIR, 0, CLK_IGNORE_UNUSED, 0), GATE(CLK_SYSREG, "sysreg", "aclk100", E4210_GATE_IP_PERIR, 0, CLK_IGNORE_UNUSED, 0), GATE(CLK_HDMI_CEC, "hdmi_cec", "aclk100", E4210_GATE_IP_PERIR, 11, 0, @@ -1100,7 +1100,7 @@ static struct samsung_gate_clock exynos4x12_gate_clks[] __initdata = { 0), GATE(CLK_TSADC, "tsadc", "aclk133", E4X12_GATE_BUS_FSYS1, 16, 0, 0), GATE(CLK_MIPI_HSI, "mipi_hsi", "aclk133", GATE_IP_FSYS, 10, 0, 0), - GATE(CLK_CHIPID, "chipid", "aclk100", E4X12_GATE_IP_PERIR, 0, 0, 0), + GATE(CLK_CHIPID, "chipid", "aclk100", E4X12_GATE_IP_PERIR, 0, CLK_IGNORE_UNUSED, 0), GATE(CLK_SYSREG, "sysreg", "aclk100", E4X12_GATE_IP_PERIR, 1, CLK_IGNORE_UNUSED, 0), GATE(CLK_HDMI_CEC, "hdmi_cec", "aclk100", E4X12_GATE_IP_PERIR, 11, 0, -- 2.47.2