clk: exynos7: Mark aclk_fsys1_200 as critical

BugLink: https://bugs.launchpad.net/bugs/1931292
commit 34138a59b92c1a30649a18ec442d2e61f3bc34dd upstream.

This clock must be always enabled to allow access to any registers in
fsys1 CMU. Until proper solution based on runtime PM is applied
(similar to what was done for Exynos5433), mark that clock as critical
so it won't be disabled.

It was observed on Samsung Galaxy S6 device (based on Exynos7420), where
UFS module is probed before pmic used to power that device.
In this case defer probe was happening and that clock was disabled by
UFS driver, causing whole boot to hang on next CMU access.

Fixes: 753195a749a6 ("clk: samsung: exynos7: Correct CMU_FSYS1 clocks names")
Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/linux-clk/20201024154346.9589-1-pawel.mikolaj.chmiel@gmail.com
[s.nawrocki: Added comment in the code]
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/clk/samsung/clk-exynos7.c b/drivers/clk/samsung/clk-exynos7.c
index 87ee1bad9a9a859206b37714279c3b8bc3cda159..4a5d2a914bd668e89a8a902db747ffe5c1307ab2 100644 (file)
--- a/drivers/clk/samsung/clk-exynos7.c
+++ b/drivers/clk/samsung/clk-exynos7.c
@@ -537,8 +537,13 @@ static const struct samsung_gate_clock top1_gate_clks[] __initconst = {
        GATE(CLK_ACLK_FSYS0_200, "aclk_fsys0_200", "dout_aclk_fsys0_200",
                ENABLE_ACLK_TOP13, 28, CLK_SET_RATE_PARENT |
                CLK_IS_CRITICAL, 0),
+       /*
+        * This clock is required for the CMU_FSYS1 registers access, keep it
+        * enabled permanently until proper runtime PM support is added.
+        */
        GATE(CLK_ACLK_FSYS1_200, "aclk_fsys1_200", "dout_aclk_fsys1_200",
-               ENABLE_ACLK_TOP13, 24, CLK_SET_RATE_PARENT, 0),
+               ENABLE_ACLK_TOP13, 24, CLK_SET_RATE_PARENT |
+               CLK_IS_CRITICAL, 0),
 
        GATE(CLK_SCLK_PHY_FSYS1_26M, "sclk_phy_fsys1_26m",
                "dout_sclk_phy_fsys1_26m", ENABLE_SCLK_TOP1_FSYS11,