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authorLevin Du <djw@t-chip.com.cn>2018-08-04 15:31:02 +0800
committerHeiko Stuebner <heiko@sntech.de>2018-08-06 23:46:52 +0200
commit640332d1a089909df08bc9f3e42888a2019c66e2 (patch)
treedc7be9e8f52c6f5a53c88b0455cac3ba2ce7e873 /drivers/clk
parenta64ad008980c65d38e6cf6858429c78e6b740c41 (diff)
clk: rockchip: Add pclk_rkpwm_pmu to PMU critical clocks in rk3399
PWM2 is commonly used to control voltage of PWM regulator of VDD_LOG in RK3399. On the Firefly-RK3399 board, PWM2 outputs 40 KHz square wave from power on and the VDD_LOG is about 0.9V. When the kernel boots normally into the system, the PWM2 keeps outputing PWM signal. But the kernel hangs randomly after "Starting kernel ..." line on that board. When it happens, PWM2 outputs high level which causes VDD_LOG drops to 0.4V below the normal operating voltage. By adding "pclk_rkpwm_pmu" to the rk3399_pmucru_critical_clocks array, PWM clock is ensured to be prepared at startup and the PWM2 output is normal. After repeated tests, the early boot hang is gone. This patch works on both Firefly-RK3399 and ROC-RK3399-PC boards. Signed-off-by: Levin Du <djw@t-chip.com.cn> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Diffstat (limited to 'drivers/clk')
-rw-r--r--drivers/clk/rockchip/clk-rk3399.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/clk/rockchip/clk-rk3399.c b/drivers/clk/rockchip/clk-rk3399.c
index 2a8634a52856..5a628148f3f0 100644
--- a/drivers/clk/rockchip/clk-rk3399.c
+++ b/drivers/clk/rockchip/clk-rk3399.c
@@ -1523,6 +1523,7 @@ static const char *const rk3399_pmucru_critical_clocks[] __initconst = {
"pclk_pmu_src",
"fclk_cm0s_src_pmu",
"clk_timer_src_pmu",
+ "pclk_rkpwm_pmu",
};
static void __init rk3399_clk_init(struct device_node *np)