[PATCH] clk: samsung: exynos5420: Mark CLK_ACLK432_SCALER as CLK_IS_CRITICAL

From: Javier Martinez Canillas
Date: Fri Jan 20 2017 - 05:41:56 EST


On Exynos5800 SoC the SCALER block uses 2 input clocks: CLK_ACLK_300_GSCL
and CLK_ACLK432_SCALER, so both needs to be ungated in order to access it.

But Exynos5420 only has the CLK_ACLK_300_GSCL as gsc_pd clk. So just using
this definition from exynos5420.dtsi in Exynos5800 leads to the following:

[ 227.008559] Unhandled fault: imprecise external abort (0x1c06) at 0x00048e14
[ 227.015116] pgd = ed5dc000
[ 227.017213] [00048e14] *pgd=b17c6835
[ 227.020889] Internal error: : 1c06 [#1] PREEMPT SMP ARM
...
[ 227.241585] [<bf2429bc>] (gsc_wait_reset [exynos_gsc]) from [<bf24009c>] (gsc_runtime_resume+0x9c/0xec [exynos_gsc])
[ 227.252331] [<bf24009c>] (gsc_runtime_resume [exynos_gsc]) from [<c042e488>] (genpd_runtime_resume+0x120/0x1d4)
[ 227.262294] [<c042e488>] (genpd_runtime_resume) from [<c04241c0>] (__rpm_callback+0xc8/0x218)

domain status slaves
/device runtime status
----------------------------------------------------------------------
power-domain@100440C0 on
/devices/platform/soc/14450000.mixer active
/devices/platform/soc/14530000.hdmi active
power-domain@10044120 on
power-domain@10044060 off-0
power-domain@10044020 on
power-domain@10044000 on
/devices/platform/soc/13e00000.video-scaler suspended
/devices/platform/soc/13e10000.video-scaler resuming

So until a proper solution based on runtime PM gets merged, mark the clock
as critical to prevent it to be gated.

Suggested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Signed-off-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx>

---

drivers/clk/samsung/clk-exynos5420.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
index 8c8b495cbf0d..9876ec28b94c 100644
--- a/drivers/clk/samsung/clk-exynos5420.c
+++ b/drivers/clk/samsung/clk-exynos5420.c
@@ -586,7 +586,7 @@ static const struct samsung_gate_clock exynos5800_gate_clks[] __initconst = {
GATE(CLK_ACLK550_CAM, "aclk550_cam", "mout_user_aclk550_cam",
GATE_BUS_TOP, 24, 0, 0),
GATE(CLK_ACLK432_SCALER, "aclk432_scaler", "mout_user_aclk432_scaler",
- GATE_BUS_TOP, 27, 0, 0),
+ GATE_BUS_TOP, 27, CLK_IS_CRITICAL, 0),
};

static const struct samsung_mux_clock exynos5420_mux_clks[] __initconst = {
--
2.7.4