From: Marek Szyprowski m.szyprowski@samsung.com
[ 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 m.szyprowski@samsung.com Link: https://lore.kernel.org/r/20200922124046.10496-1-m.szyprowski@samsung.com Reviewed-by: Krzysztof Kozlowski krzk@kernel.org Acked-by: Sylwester Nawrocki s.nawrocki@samsung.com Signed-off-by: Stephen Boyd sboyd@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 51564fc23c639..f4086287bb71b 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,