| Message ID | 20200922124046.10496-1-m.szyprowski@samsung.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | clk: samsung: exynos4: mark 'chipid' clock as CLK_IGNORE_UNUSED | expand |
On Tue, 22 Sep 2020 at 14:40, Marek Szyprowski <m.szyprowski@samsung.com> wrote: > > 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> > --- > drivers/clk/samsung/clk-exynos4.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org> Best regards, Krzysztof
On 22.09.2020 14:40, Marek Szyprowski wrote: > 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> Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Quoting Marek Szyprowski (2020-09-22 05:40:46) > 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> > --- Applied to clk-fixes
diff --git a/drivers/clk/samsung/clk-exynos4.c b/drivers/clk/samsung/clk-exynos4.c index 436fcd279951..bf13e29a655c 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,
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> --- drivers/clk/samsung/clk-exynos4.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)