From f3bb0f796f5ffe32f0fbdce5b1b12eb85511158f Mon Sep 17 00:00:00 2001
From: Marek Szyprowski <m.szyprowski@samsung.com>
Date: Tue, 22 Sep 2020 14:40:46 +0200
Subject: [PATCH] clk: samsung: exynos4: mark 'chipid' clock as CLK_IGNORE_UNUSED
Git-commit: f3bb0f796f5ffe32f0fbdce5b1b12eb85511158f
Patch-mainline: v5.9
References: git-fixes
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 51564fc23c63..f4086287bb71 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,
--
2.16.4