diff options
author | Shawn Guo <shawn.guo@linaro.org> | 2015-04-29 08:07:03 +0300 |
---|---|---|
committer | Shawn Guo <shawn.guo@linaro.org> | 2015-06-03 09:49:18 +0300 |
commit | 35e2916f70e3be767c5c8ef6cc80bc5398b8914c (patch) | |
tree | 9168d5d7f16b86fb402f3d521adf1efd770f04c9 /arch/arm/mach-imx/common.h | |
parent | de8e434d09f253369621e994da1833703c5c51d6 (diff) | |
download | linux-35e2916f70e3be767c5c8ef6cc80bc5398b8914c.tar.xz |
ARM: imx6: initialize CCM_CLPCR_LPM into RUN mode earlier
Commit 4631960d26da ("ARM: imx6: set initial power mode in pm function")
moves imx6_set_lpm() from clock init function into
imx6_pm_common_init(). This causes a hang when cpuidle support is
enabled. The reason for that is ARM core clock is shut down
unexpectedly by WAIT mode. It happens with the following call stack:
cpuidle_register_governor()
cpuidle_switch_governor()
cpuidle_uninstall_idle_handler()
synchronize_sched()
wait_rcu_gp()
wait_for_completion()
When wait_for_completion() is called as above, all cores are idle/WFI.
Hence, the reset value of CCM_CLPCR_LPM - WAIT mode, will trigger a
hardware shutdown of the ARM core clock.
To fix the regression, we need to ensure that CCM_CLPCR_LPM is
initialized into RUN mode earlier than cpuidle governor registration,
which is a postcore_initcall. This patch creates function
imx6_pm_ccm_init() to map CCM block and initialize CCM_CLPCR_LPM into
RUN mode, and have the function called from machine .init_irq hook,
which should be early enough.
Reported-by: Kevin Hilman <khilman@kernel.org>
Fixes: 8fb76a07e2cb ("ARM: imx6: set initial power mode in pm function")
Tested-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Tyler Baker <tyler.baker@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Diffstat (limited to 'arch/arm/mach-imx/common.h')
-rw-r--r-- | arch/arm/mach-imx/common.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h index d1e2873f807e..fbd86f1b7f3b 100644 --- a/arch/arm/mach-imx/common.h +++ b/arch/arm/mach-imx/common.h @@ -123,6 +123,7 @@ static inline void v7_cpu_resume(void) {} static inline void imx6_suspend(void __iomem *ocram_vbase) {} #endif +void imx6_pm_ccm_init(const char *ccm_compat); void imx6q_pm_init(void); void imx6dl_pm_init(void); void imx6sl_pm_init(void); |