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authorShawn Guo <shawn.guo@linaro.org>2015-04-29 13:07:03 +0800
committerShawn Guo <shawn.guo@linaro.org>2015-06-03 14:49:18 +0800
commit35e2916f70e3be767c5c8ef6cc80bc5398b8914c (patch)
tree9168d5d7f16b86fb402f3d521adf1efd770f04c9
parentde8e434d09f253369621e994da1833703c5c51d6 (diff)
downloadlinux-linaro-stable-35e2916f70e3be767c5c8ef6cc80bc5398b8914c.tar.gz
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>
-rw-r--r--arch/arm/mach-imx/common.h1
-rw-r--r--arch/arm/mach-imx/mach-imx6q.c1
-rw-r--r--arch/arm/mach-imx/mach-imx6sl.c1
-rw-r--r--arch/arm/mach-imx/mach-imx6sx.c1
-rw-r--r--arch/arm/mach-imx/pm-imx6.c28
5 files changed, 22 insertions, 10 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);
diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index 3ab61549ce0f..9602cc12d2f1 100644
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c
@@ -393,6 +393,7 @@ static void __init imx6q_init_irq(void)
imx_init_l2cache();
imx_src_init();
irqchip_init();
+ imx6_pm_ccm_init("fsl,imx6q-ccm");
}
static const char * const imx6q_dt_compat[] __initconst = {
diff --git a/arch/arm/mach-imx/mach-imx6sl.c b/arch/arm/mach-imx/mach-imx6sl.c
index 12a1b098fc6a..300326373166 100644
--- a/arch/arm/mach-imx/mach-imx6sl.c
+++ b/arch/arm/mach-imx/mach-imx6sl.c
@@ -66,6 +66,7 @@ static void __init imx6sl_init_irq(void)
imx_init_l2cache();
imx_src_init();
irqchip_init();
+ imx6_pm_ccm_init("fsl,imx6sl-ccm");
}
static const char * const imx6sl_dt_compat[] __initconst = {
diff --git a/arch/arm/mach-imx/mach-imx6sx.c b/arch/arm/mach-imx/mach-imx6sx.c
index f17b7004c24b..6a0b0614de29 100644
--- a/arch/arm/mach-imx/mach-imx6sx.c
+++ b/arch/arm/mach-imx/mach-imx6sx.c
@@ -86,6 +86,7 @@ static void __init imx6sx_init_irq(void)
imx_init_l2cache();
imx_src_init();
irqchip_init();
+ imx6_pm_ccm_init("fsl,imx6sx-ccm");
}
static void __init imx6sx_init_late(void)
diff --git a/arch/arm/mach-imx/pm-imx6.c b/arch/arm/mach-imx/pm-imx6.c
index 27bc80dab2d8..b01650d94f91 100644
--- a/arch/arm/mach-imx/pm-imx6.c
+++ b/arch/arm/mach-imx/pm-imx6.c
@@ -89,7 +89,6 @@ struct imx6_pm_base {
struct imx6_pm_socdata {
u32 ddr_type;
- const char *ccm_compat;
const char *mmdc_compat;
const char *src_compat;
const char *iomuxc_compat;
@@ -139,7 +138,6 @@ static const u32 imx6sx_mmdc_io_offset[] __initconst = {
};
static const struct imx6_pm_socdata imx6q_pm_data __initconst = {
- .ccm_compat = "fsl,imx6q-ccm",
.mmdc_compat = "fsl,imx6q-mmdc",
.src_compat = "fsl,imx6q-src",
.iomuxc_compat = "fsl,imx6q-iomuxc",
@@ -149,7 +147,6 @@ static const struct imx6_pm_socdata imx6q_pm_data __initconst = {
};
static const struct imx6_pm_socdata imx6dl_pm_data __initconst = {
- .ccm_compat = "fsl,imx6q-ccm",
.mmdc_compat = "fsl,imx6q-mmdc",
.src_compat = "fsl,imx6q-src",
.iomuxc_compat = "fsl,imx6dl-iomuxc",
@@ -159,7 +156,6 @@ static const struct imx6_pm_socdata imx6dl_pm_data __initconst = {
};
static const struct imx6_pm_socdata imx6sl_pm_data __initconst = {
- .ccm_compat = "fsl,imx6sl-ccm",
.mmdc_compat = "fsl,imx6sl-mmdc",
.src_compat = "fsl,imx6sl-src",
.iomuxc_compat = "fsl,imx6sl-iomuxc",
@@ -169,7 +165,6 @@ static const struct imx6_pm_socdata imx6sl_pm_data __initconst = {
};
static const struct imx6_pm_socdata imx6sx_pm_data __initconst = {
- .ccm_compat = "fsl,imx6sx-ccm",
.mmdc_compat = "fsl,imx6sx-mmdc",
.src_compat = "fsl,imx6sx-src",
.iomuxc_compat = "fsl,imx6sx-iomuxc",
@@ -553,16 +548,11 @@ put_node:
static void __init imx6_pm_common_init(const struct imx6_pm_socdata
*socdata)
{
- struct device_node *np;
struct regmap *gpr;
int ret;
- np = of_find_compatible_node(NULL, NULL, socdata->ccm_compat);
- ccm_base = of_iomap(np, 0);
WARN_ON(!ccm_base);
- imx6_set_lpm(WAIT_CLOCKED);
-
if (IS_ENABLED(CONFIG_SUSPEND)) {
ret = imx6q_suspend_init(socdata);
if (ret)
@@ -583,6 +573,24 @@ static void __init imx6_pm_common_init(const struct imx6_pm_socdata
IMX6Q_GPR1_GINT);
}
+void __init imx6_pm_ccm_init(const char *ccm_compat)
+{
+ struct device_node *np;
+ u32 val;
+
+ np = of_find_compatible_node(NULL, NULL, ccm_compat);
+ ccm_base = of_iomap(np, 0);
+ BUG_ON(!ccm_base);
+
+ /*
+ * Initialize CCM_CLPCR_LPM into RUN mode to avoid ARM core
+ * clock being shut down unexpectedly by WAIT mode.
+ */
+ val = readl_relaxed(ccm_base + CLPCR);
+ val &= ~BM_CLPCR_LPM;
+ writel_relaxed(val, ccm_base + CLPCR);
+}
+
void __init imx6q_pm_init(void)
{
imx6_pm_common_init(&imx6q_pm_data);