OMAP3+: PM: SR fixes

From: Colin Cross <[email protected]>

omap_sr_disable_reset_volt is called with irqs off in omapx_enter_sleep, as part of idle sequence, this eventually calls sr_disable and pm_runtime_put_sync. pm_runtime_put_sync calls rpm_idle, which will enable interrupts in order to call the callback. In this short interval when interrupts are enabled, scenarios such as the following can occur:
while interrupts are enabled, the timer interrupt that is supposed to wake the device out of idle occurs and is acked, so when the CPU finally goes to off, the timer is already gone, missing a wakeup event.

Further, as the documentation for runtime states:"
However, subsystems can use the pm_runtime_irq_safe() helper function to tell the PM core that a device's ->runtime_suspend() and ->runtime_resume() callbacks should be invoked in atomic context with interrupts disabled (->runtime_idle() is still invoked the default way)."

Hence, replace pm_runtime_put_sync with pm_runtime_put_sync_suspend to invoke the suspend handler and shut off the fclk for SmartReflex module instead of using the idle handler in interrupt disabled context.

Signed-off-by Nishanth Menon <[email protected]>

Signed-off-by Colin Cross <[email protected]>

Suspend and Resume paths are safe enough to do it in the standard LDM suspend/resume handlers where one can sleep. Add suspend/resume handlers for SmartReflex.

Signed-off-by Nishanth Menon <[email protected]>

---
 arch/arm/mach-omap2/smartreflex.c |   87 +++++++++++++++++++++++++++++++++++++
 1 files changed, 87 insertions(+), 0 deletions(-)

arch/arm/mach-omap2/smartreflex.c +1 -0

index 33a027f..fb90bd2 100644
@@ -39,6 +39,7 @@ struct omap_sr {
 	int				ip_type;
 	int				nvalue_count;
 	bool				autocomp_active;
+	bool				is_suspended;
 	u32				clk_length;
 	u32				err_weight;
 	u32				err_minlimit;

Hi,

Quoted 25 lines · Nishanth Menon

Suspend and Resume paths are safe enough to do it in the standard LDM suspend/resume handlers where one can sleep. Add suspend/resume handlers for SmartReflex.

Signed-off-by Nishanth Menon <[email protected]>

---
?arch/arm/mach-omap2/smartreflex.c | ? 87 +++++++++++++++++++++++++++++++++++++ ?1 files changed, 87 insertions(+), 0 deletions(-)

arch/arm/mach-omap2/smartreflex.c +1 -0

index 33a027f..fb90bd2 100644
@@ -39,6 +39,7 @@ struct omap_sr {
 ? ? ? int ? ? ? ? ? ? ? ? ? ? ? ? ? ? ip_type;
 ? ? ? int ? ? ? ? ? ? ? ? ? ? ? ? ? ? nvalue_count;
 ? ? ? bool ? ? ? ? ? ? ? ? ? ? ? ? ? ?autocomp_active;
+ ? ? bool ? ? ? ? ? ? ? ? ? ? ? ? ? ?is_suspended;
 ? ? ? u32 ? ? ? ? ? ? ? ? ? ? ? ? ? ? clk_length;
 ? ? ? u32 ? ? ? ? ? ? ? ? ? ? ? ? ? ? err_weight;
 ? ? ? u32 ? ? ? ? ? ? ? ? ? ? ? ? ? ? err_minlimit;

@@ -684,6 +685,12 @@ void omap_sr_enable(struct voltagedomain *voltdm)
 ? ? ? if (!sr->autocomp_active)
 ? ? ? ? ? ? ? return;
 

arch/arm/mach-omap2/smartreflex.c void omap_sr_enable(struct voltagedomain *voltdm) · line 691

Quoted 4 lines

arch/arm/mach-omap2/smartreflex.c +4 -0

+ ? ? if (sr->is_suspended) {
+ ? ? ? ? ? ? dev_dbg(&sr->pdev->dev, "%s: in suspended state\n", __func__);
+ ? ? ? ? ? ? return;
+ ? ? }

I wonder why you get these called if you're in suspend state. If this is called by some other driver, then shouldn't you pm_runtime_get_sync(); do_whatever_you_need_to_do(); and pm_runtime_put(); rather then just returning ?

Suspend and Resume paths are safe enough to do it in

the standard LDM suspend/resume handlers where one can sleep. Add suspend/resume handlers for SmartReflex.

arch/arm/mach-omap2/smartreflex.c +0 -0

 	if (!sr_class || !(sr_class->enable) || !(sr_class->configure)) {
 		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not"
 			"registered\n", __func__);