Hi,

On Monday, July 14, 2014 11:54:48 AM Tomasz Figa wrote:
> Hi Kukjin,
> 
> On 25.06.2014 13:52, Tomasz Figa wrote:
> > 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 <t.f...@samsung.com>
> > ---
> >  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

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