From f3bb0f796f5ffe32f0fbdce5b1b12eb85511158f 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 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 --- 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 51564fc..f408628 100644 --- a/drivers/clk/samsung/clk-exynos4.c +++ b/drivers/clk/samsung/clk-exynos4.c @@ -927,7 +927,7 @@ static const struct samsung_gate_clock exynos4210_gate_clks[] __initconst = { 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, @@ -969,7 +969,7 @@ static const struct samsung_gate_clock exynos4x12_gate_clks[] __initconst = { 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, -- 2.7.4