On Sun, Mar 22, 2020 at 04:22:24PM -0400, Sasha Levin wrote:

On Sun, Mar 22, 2020 at 07:50:22PM +0100, Clemens Gruber wrote:

...

Hi,

On Thu, Jan 16, 2020 at 03:18:49PM +0100, Rouven Czerwinski wrote:

...

From: Ahmad Fatoum a.fatoum@pengutronix.de

This function is not only needed by the platform suspend code, but is also reused as the CPU resume function when the ARM cores can be powered down completely in deep idle, which is the case on i.MX6SX and i.MX6UL(L).

Providing the static inline stub whenever CONFIG_SUSPEND is disabled means that those platforms will hang on resume from cpuidle if suspend is disabled.

So there are two problems:

• The static inline stub masks the linker error
• The function is not available where needed

Fix both by just building the function unconditionally, when CONFIG_SOC_IMX6 is enabled. The actual code is three instructions long, so it's arguably ok to just leave it in for all i.MX6 kernel configurations.

Fixes: 05136f0897b5 ("ARM: imx: support arm power off in cpuidle for i.mx6sx") Signed-off-by: Lucas Stach l.stach@pengutronix.de Signed-off-by: Ahmad Fatoum a.fatoum@pengutronix.de Signed-off-by: Rouven Czerwinski r.czerwinski@pengutronix.de

---

arch/arm/mach-imx/Makefile | 2 ++ arch/arm/mach-imx/common.h | 4 ++-- arch/arm/mach-imx/resume-imx6.S | 24 ++++++++++++++++++++++++ arch/arm/mach-imx/suspend-imx6.S | 14 -------------- 4 files changed, 28 insertions(+), 16 deletions(-) create mode 100644 arch/arm/mach-imx/resume-imx6.S

diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile index 35ff620537e6..03506ce46149 100644 --- a/arch/arm/mach-imx/Makefile +++ b/arch/arm/mach-imx/Makefile @@ -91,6 +91,8 @@ AFLAGS_suspend-imx6.o :=-Wa,-march=armv7-a obj-$(CONFIG_SOC_IMX6) += suspend-imx6.o obj-$(CONFIG_SOC_IMX53) += suspend-imx53.o endif +AFLAGS_resume-imx6.o :=-Wa,-march=armv7-a +obj-$(CONFIG_SOC_IMX6) += resume-imx6.o obj-$(CONFIG_SOC_IMX6) += pm-imx6.o

obj-$(CONFIG_SOC_IMX1) += mach-imx1.o diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h index 912aeceb4ff8..5aa5796cff0e 100644 --- a/arch/arm/mach-imx/common.h +++ b/arch/arm/mach-imx/common.h @@ -109,17 +109,17 @@ void imx_cpu_die(unsigned int cpu); int imx_cpu_kill(unsigned int cpu);

#ifdef CONFIG_SUSPEND -void v7_cpu_resume(void); void imx53_suspend(void __iomem *ocram_vbase); extern const u32 imx53_suspend_sz; void imx6_suspend(void __iomem *ocram_vbase); #else -static inline void v7_cpu_resume(void) {} static inline void imx53_suspend(void __iomem *ocram_vbase) {} static const u32 imx53_suspend_sz; static inline void imx6_suspend(void __iomem *ocram_vbase) {} #endif

+void v7_cpu_resume(void);

void imx6_pm_ccm_init(const char *ccm_compat); void imx6q_pm_init(void); void imx6dl_pm_init(void); diff --git a/arch/arm/mach-imx/resume-imx6.S b/arch/arm/mach-imx/resume-imx6.S new file mode 100644 index 000000000000..5bd1ba7ef15b --- /dev/null +++ b/arch/arm/mach-imx/resume-imx6.S @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/*

• • Copyright 2014 Freescale Semiconductor, Inc.
• */

+#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/asm-offsets.h> +#include <asm/hardware/cache-l2x0.h> +#include "hardware.h"

+/*

• • The following code must assume it is running from physical address
• • where absolute virtual addresses to the data section have to be
• • turned into relative ones.
• */

+ENTRY(v7_cpu_resume)

• bl v7_invalidate_l1

+#ifdef CONFIG_CACHE_L2X0

• bl l2c310_early_resume

+#endif

• b cpu_resume

+ENDPROC(v7_cpu_resume) diff --git a/arch/arm/mach-imx/suspend-imx6.S b/arch/arm/mach-imx/suspend-imx6.S index 062391ff13da..1eabf2d2834b 100644 --- a/arch/arm/mach-imx/suspend-imx6.S +++ b/arch/arm/mach-imx/suspend-imx6.S @@ -327,17 +327,3 @@ resume:

ret lr ENDPROC(imx6_suspend)

-/*

• • The following code must assume it is running from physical address
• • where absolute virtual addresses to the data section have to be
• • turned into relative ones.
• */

-ENTRY(v7_cpu_resume)

• bl v7_invalidate_l1

-#ifdef CONFIG_CACHE_L2X0

• bl l2c310_early_resume

-#endif

• b cpu_resume

-ENDPROC(v7_cpu_resume)

2.25.0

This patch broke the build for our i.MX6 kernel.

I am referring to commits 512a928aff in mainline and 7199cb65bb in linux-stable.

In our kernel, neither CONFIG_PM nor CONFIG_SUSPEND are set. Therefore, ARM_CPU_SUSPEND is also unset, which means that sleep.S (containing cpu_resume) is not built.

With this patch, ld reports the following error: arch/arm/mach-imx/resume-imx6.o: in function `v7_cpu_resume': (.text+0x8): undefined reference to `cpu_resume'

Is this a problem with Linus's tree as well?

Yes, it affects Linus's tree and linux-stable.

Reverting 512a928aff in mainline (7199cb65bb in linux-stable) fixes the build error for us.

Thanks, Clemens