Hi,

On Monday, July 14, 2014 11:54:48 AM Tomasz Figa wrote:

Hi Kukjin,

On 25.06.2014 13:52, Tomasz Figa wrote:

quoted

Due to recent consolidation of Exynos suspend and cpuidle code, some
parts of suspend and resume sequences are executed two times, once from
exynos_pm_syscore_ops and then from exynos_cpu_pm_notifier() and thus it
breaks suspend, at least on Exynos4-based boards.

This patch fixes the issue by removing exynos_pm_syscore_ops completely
and making the code rely only on CPU PM notifier.

Tested on Exynos4210-based Trats board.

Signed-off-by: Tomasz Figa <redacted>
---
 arch/arm/mach-exynos/pm.c | 23 ++++-------------------
 1 file changed, 4 insertions(+), 19 deletions(-)

Changes since v1:
 - rebased onto Kukjin's fixes branch.

diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
index 202ca73..f23cc77 100644
--- a/arch/arm/mach-exynos/pm.c
+++ b/arch/arm/mach-exynos/pm.c

@@ -364,11 +364,6 @@ early_wakeup:
 	return;
 }
 
-static struct syscore_ops exynos_pm_syscore_ops = {
-	.suspend	= exynos_pm_suspend,
-	.resume		= exynos_pm_resume,
-};
-
 /*
  * Suspend Ops
  */

@@ -438,22 +433,13 @@ static int exynos_cpu_pm_notifier(struct notifier_block *self,
 
 	switch (cmd) {
 	case CPU_PM_ENTER:
-		if (cpu == 0) {
-			exynos_pm_central_suspend();
-			if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9)
-				exynos_cpu_save_register();
-		}
+		if (cpu == 0)
+			exynos_pm_suspend();
 		break;
 
 	case CPU_PM_EXIT:
-		if (cpu == 0) {
-			if (read_cpuid_part_number() ==
-					ARM_CPU_PART_CORTEX_A9) {
-				scu_enable(S5P_VA_SCU);
-				exynos_cpu_restore_register();
-			}
-			exynos_pm_central_resume();
-		}
+		if (cpu == 0)
+			exynos_pm_resume();
 		break;
 	}
 

@@ -478,6 +464,5 @@ void __init exynos_pm_init(void)
 	tmp |= ((0xFF << 8) | (0x1F << 1));
 	__raw_writel(tmp, S5P_WAKEUP_MASK);
 
-	register_syscore_ops(&exynos_pm_syscore_ops);
 	suspend_set_ops(&exynos_suspend_ops);
 }

Please consider this patch for next fixes pull request. Without it
suspend/resume is broken for Exynos4 and probably other SoCs. This patch
just restores the sequence from before the patch moving things to PM
notifier, so I don't think it should need any special treatment.

Your patch fixes the regression and is a step in the good direction but it
seems that it needs a bit more work:

Your patch adds to cpuidle AFTR code path restoring of exynos_core_save and
exynos5_sys_save registers without saving them first (restoring is done
through exynos_pm_resume() which is used by both suspend and cpuidle while
saving is done through exynos_pm_prepare() which is used only by suspend). 

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics