| Message ID | 20150429060446.GA27573@dragon (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Shawn Guo <shawn.guo@linaro.org> writes: > Hi Kevin, > > On Tue, Apr 28, 2015 at 11:42:48AM -0700, Kevin Hilman wrote: >> Hi Shawn, >> >> On Sun, Apr 26, 2015 at 7:31 AM, Shawn Guo <shawn.guo@linaro.org> wrote: >> > Rather than setting initial low-power mode in every single i.MX6 clock >> > initialization function, we should really do that in pm code. Let's >> > move imx6q_set_lpm(WAIT_CLOCKED) call into imx6_pm_common_init(). >> > >> > While at it, let's rename the function to imx6_set_lpm() since it's >> > actually common for all i.MX6 SoCs. >> > >> > Signed-off-by: Shawn Guo <shawn.guo@linaro.org> >> >> Some boot failures on imx6[1] (multi_v7_defconfig) were bisected down >> to this patch. A simple revert doesn't build, so I was unable tot >> test a direct revert. However, from the boot failures you can see >> that while multi_v7_defconfig boots fail, the imx_v6_v7_defconfig >> boots fine. > > This reminds me that cpuidle support is not turned on in > imx_v6_v7_defconfig. I will send a patch to enable it for testing > coverage. > >> Disabling CONFIG_CPU_IDLE in multi_v7_defconfig allows >> this to start booting again on my wandboard quad, so I think there is >> something wrong with the cpuidle changes. > > I just tracked down the issue, and sent a fix like below. Thanks for the quick fix. > The kernelci.org boot automation farm helps. Thanks. Glad it's useful. We're doing a build/boot test of your fix now, and will keep you updated. In the mean time..., > ----8<------------------------------- > From 056a5da1b56a057762eccd52b5b6b920c7f56b14 Mon Sep 17 00:00:00 2001 > From: Shawn Guo <shawn.guo@linaro.org> > Date: Wed, 29 Apr 2015 13:07:03 +0800 > Subject: [PATCH] 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: 4631960d26da ("ARM: imx6: set initial power mode in pm function") > Signed-off-by: Shawn Guo <shawn.guo@linaro.org> ...I did a quick test of this locally on my wandboard-quad, and it's now booting with multi_v7_defconfig too. Tested-by: Kevin Hilman <khilman@linaro.org>
On Wed, Apr 29, 2015 at 09:35:28AM -0700, Kevin Hilman wrote: > ...I did a quick test of this locally on my wandboard-quad, and it's now > booting with multi_v7_defconfig too. > > Tested-by: Kevin Hilman <khilman@linaro.org> Thanks for testing, Kevin. Shawn
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);