* [PATCH] i2c: i2c-omap: fix interrupt flood during resume
@ 2012-10-05 8:55 Kalle Jokiniemi
[not found] ` <1349427316-24990-1-git-send-email-kalle.jokiniemi-4y2FMlU5MS8onNqTyK5kxQ@public.gmane.org>
0 siblings, 1 reply; 3+ messages in thread
From: Kalle Jokiniemi @ 2012-10-05 8:55 UTC (permalink / raw)
To: ben-linux-elnMNo+KYs3YtjvyW6yDsg, w.sang-bIcnvbaLZ9MEGnE8C9+IrQ,
linux-i2c-u79uwXL29TY76Z2rM5mHXA
Cc: tony-4v6yS6AI5VpBDgjK7y7TUQ, linux-omap-u79uwXL29TY76Z2rM5mHXA,
Kalle Jokiniemi
The resume_noirq enables interrupts one-by-one starting from
first one. Now if the wake up event for suspend came from i2c
device, the i2c bus irq gets enabled before the threaded
i2c device irq, causing a flood of i2c bus interrupts as the
threaded irq that should clear the event is not enabled yet.
Fixed the issue by adding suspend_late and resume_early
functions that keep i2c bus interrupts disabled until
resume_noirq has run completely.
Issue was detected doing a wake up from autosleep with
twl4030 power key on N9. Patch tested on N9.
Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi-4y2FMlU5MS8onNqTyK5kxQ@public.gmane.org>
---
drivers/i2c/busses/i2c-omap.c | 37 +++++++++++++++++++++++++++++++++++++
1 files changed, 37 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 801df60..b77b0c2 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1158,6 +1158,35 @@ omap_i2c_remove(struct platform_device *pdev)
return 0;
}
+#ifdef CONFIG_SUSPEND
+static int omap_i2c_suspend_late(struct device *dev)
+{
+
+ struct platform_device *pdev = to_platform_device(dev);
+ struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
+
+ /*
+ * The noirq_resume enables the interrupts one by one,
+ * this causes a interrupt flood if the SW irq actually reading
+ * event from i2c device is enabled only after i2c bus irq, as the
+ * irq that should clear the event is still disabled. We have to
+ * disable the bus irq until all other irqs have been enabled.
+ */
+ disable_irq(_dev->irq);
+ return 0;
+}
+
+static int omap_i2c_resume_early(struct device *dev)
+{
+
+ struct platform_device *pdev = to_platform_device(dev);
+ struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
+
+ enable_irq(_dev->irq);
+
+ return 0;
+}
+#endif
#ifdef CONFIG_PM_RUNTIME
static int omap_i2c_runtime_suspend(struct device *dev)
{
@@ -1178,10 +1207,18 @@ static int omap_i2c_runtime_resume(struct device *dev)
return 0;
}
+#endif
+#if defined(CONFIG_SUSPEND) || defined(CONFIG_PM_RUNTIME)
static struct dev_pm_ops omap_i2c_pm_ops = {
+#ifdef CONFIG_SUSPEND
+ .suspend_late = omap_i2c_suspend_late,
+ .resume_early = omap_i2c_resume_early,
+#endif
+#ifdef CONFIG_PM_RUNTIME
.runtime_suspend = omap_i2c_runtime_suspend,
.runtime_resume = omap_i2c_runtime_resume,
+#endif
};
#define OMAP_I2C_PM_OPS (&omap_i2c_pm_ops)
#else
--
1.7.4.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] i2c: i2c-omap: fix interrupt flood during resume
[not found] ` <1349427316-24990-1-git-send-email-kalle.jokiniemi-4y2FMlU5MS8onNqTyK5kxQ@public.gmane.org>
@ 2012-10-05 22:07 ` Kevin Hilman
[not found] ` <87boggmv3j.fsf-1D3HCaltpLuhEniVeURVKkEOCMrvLtNR@public.gmane.org>
0 siblings, 1 reply; 3+ messages in thread
From: Kevin Hilman @ 2012-10-05 22:07 UTC (permalink / raw)
To: Kalle Jokiniemi
Cc: ben-linux-elnMNo+KYs3YtjvyW6yDsg, w.sang-bIcnvbaLZ9MEGnE8C9+IrQ,
linux-i2c-u79uwXL29TY76Z2rM5mHXA, tony-4v6yS6AI5VpBDgjK7y7TUQ,
linux-omap-u79uwXL29TY76Z2rM5mHXA, grygorii.strashko-l0cyMroinI0
+Grygorii (who's been working on various I2C related suspend/resume
issues also)
Hi Kalle,
Kalle Jokiniemi <kalle.jokiniemi-4y2FMlU5MS8onNqTyK5kxQ@public.gmane.org> writes:
> The resume_noirq enables interrupts one-by-one starting from
> first one. Now if the wake up event for suspend came from i2c
> device, the i2c bus irq gets enabled before the threaded
> i2c device irq, causing a flood of i2c bus interrupts as the
> threaded irq that should clear the event is not enabled yet.
Ugh, another reason we need some sort of driver dependency tracking in the
driver model.
> Fixed the issue by adding suspend_late and resume_early
> functions that keep i2c bus interrupts disabled until
> resume_noirq has run completely.
Hmm, any reason we couldn't put the disable in the .suspend_noirq
callback? The reason being is that other drivers might use I2C in their
suspend or late_suspend callbacks. I'm not aware of any using I2C in
their late_suspend callbacks in mainline, but in theory I2C should work
all the way through the late callbacks.
I know it might look strange to have a disable_irq() in the noirq
callback, since IRQs are already disabled at that point, but a comment
stating that it's just there to balance the (re)enable in the
early_resume callback should be clear.
Some other minor comments below...
> Issue was detected doing a wake up from autosleep with
> twl4030 power key on N9. Patch tested on N9.
>
> Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi-4y2FMlU5MS8onNqTyK5kxQ@public.gmane.org>
> ---
> drivers/i2c/busses/i2c-omap.c | 37 +++++++++++++++++++++++++++++++++++++
> 1 files changed, 37 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 801df60..b77b0c2 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -1158,6 +1158,35 @@ omap_i2c_remove(struct platform_device *pdev)
> return 0;
> }
>
> +#ifdef CONFIG_SUSPEND
This should be CONFIG_PM_SLEEP in order to cover hibernation also.
> +static int omap_i2c_suspend_late(struct device *dev)
> +{
> +
> + struct platform_device *pdev = to_platform_device(dev);
> + struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
> +
> + /*
> + * The noirq_resume enables the interrupts one by one,
> + * this causes a interrupt flood if the SW irq actually reading
> + * event from i2c device is enabled only after i2c bus irq, as the
> + * irq that should clear the event is still disabled. We have to
> + * disable the bus irq until all other irqs have been enabled.
> + */
This comment probably belongs in the resume handler.
> + disable_irq(_dev->irq);
> + return 0;
> +}
> +
> +static int omap_i2c_resume_early(struct device *dev)
> +{
> +
> + struct platform_device *pdev = to_platform_device(dev);
> + struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
> +
> + enable_irq(_dev->irq);
> +
> + return 0;
> +}
> +#endif
> #ifdef CONFIG_PM_RUNTIME
> static int omap_i2c_runtime_suspend(struct device *dev)
> {
> @@ -1178,10 +1207,18 @@ static int omap_i2c_runtime_resume(struct device *dev)
>
> return 0;
> }
> +#endif
>
> +#if defined(CONFIG_SUSPEND) || defined(CONFIG_PM_RUNTIME)
#ifdef CONFIG_PM will cover this
> static struct dev_pm_ops omap_i2c_pm_ops = {
> +#ifdef CONFIG_SUSPEND
again, CONFIG_PM_SLEEP here
> + .suspend_late = omap_i2c_suspend_late,
> + .resume_early = omap_i2c_resume_early,
> +#endif
> +#ifdef CONFIG_PM_RUNTIME
> .runtime_suspend = omap_i2c_runtime_suspend,
> .runtime_resume = omap_i2c_runtime_resume,
> +#endif
> };
> #define OMAP_I2C_PM_OPS (&omap_i2c_pm_ops)
> #else
Kevin
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] i2c: i2c-omap: fix interrupt flood during resume
[not found] ` <87boggmv3j.fsf-1D3HCaltpLuhEniVeURVKkEOCMrvLtNR@public.gmane.org>
@ 2012-10-08 6:21 ` Kalle Jokiniemi
0 siblings, 0 replies; 3+ messages in thread
From: Kalle Jokiniemi @ 2012-10-08 6:21 UTC (permalink / raw)
To: Kevin Hilman
Cc: ben-linux-elnMNo+KYs3YtjvyW6yDsg, w.sang-bIcnvbaLZ9MEGnE8C9+IrQ,
linux-i2c-u79uwXL29TY76Z2rM5mHXA, tony-4v6yS6AI5VpBDgjK7y7TUQ,
linux-omap-u79uwXL29TY76Z2rM5mHXA, grygorii.strashko-l0cyMroinI0
pe, 2012-10-05 kello 15:07 -0700, Kevin Hilman kirjoitti:
> +Grygorii (who's been working on various I2C related suspend/resume
> issues also)
>
> Hi Kalle,
>
> Kalle Jokiniemi <kalle.jokiniemi-4y2FMlU5MS8onNqTyK5kxQ@public.gmane.org> writes:
>
> > The resume_noirq enables interrupts one-by-one starting from
> > first one. Now if the wake up event for suspend came from i2c
> > device, the i2c bus irq gets enabled before the threaded
> > i2c device irq, causing a flood of i2c bus interrupts as the
> > threaded irq that should clear the event is not enabled yet.
>
> Ugh, another reason we need some sort of driver dependency tracking in the
> driver model.
>
> > Fixed the issue by adding suspend_late and resume_early
> > functions that keep i2c bus interrupts disabled until
> > resume_noirq has run completely.
>
> Hmm, any reason we couldn't put the disable in the .suspend_noirq
> callback?
I just liked the symmetry of late/early.
> The reason being is that other drivers might use I2C in their
> suspend or late_suspend callbacks. I'm not aware of any using I2C in
> their late_suspend callbacks in mainline, but in theory I2C should work
> all the way through the late callbacks.
Makes sense, I'll change that.
>
> I know it might look strange to have a disable_irq() in the noirq
> callback, since IRQs are already disabled at that point, but a comment
> stating that it's just there to balance the (re)enable in the
> early_resume callback should be clear.
>
> Some other minor comments below...
>
> > Issue was detected doing a wake up from autosleep with
> > twl4030 power key on N9. Patch tested on N9.
> >
> > Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi-4y2FMlU5MS8onNqTyK5kxQ@public.gmane.org>
> > ---
> > drivers/i2c/busses/i2c-omap.c | 37 +++++++++++++++++++++++++++++++++++++
> > 1 files changed, 37 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> > index 801df60..b77b0c2 100644
> > --- a/drivers/i2c/busses/i2c-omap.c
> > +++ b/drivers/i2c/busses/i2c-omap.c
> > @@ -1158,6 +1158,35 @@ omap_i2c_remove(struct platform_device *pdev)
> > return 0;
> > }
> >
> > +#ifdef CONFIG_SUSPEND
>
> This should be CONFIG_PM_SLEEP in order to cover hibernation also.
Ok, I'll fix these, thanks.
>
> > +static int omap_i2c_suspend_late(struct device *dev)
> > +{
> > +
> > + struct platform_device *pdev = to_platform_device(dev);
> > + struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
> > +
> > + /*
> > + * The noirq_resume enables the interrupts one by one,
> > + * this causes a interrupt flood if the SW irq actually reading
> > + * event from i2c device is enabled only after i2c bus irq, as the
> > + * irq that should clear the event is still disabled. We have to
> > + * disable the bus irq until all other irqs have been enabled.
> > + */
>
> This comment probably belongs in the resume handler.
Ok. I'll move it.
- Kalle
>
> > + disable_irq(_dev->irq);
> > + return 0;
> > +}
> > +
> > +static int omap_i2c_resume_early(struct device *dev)
> > +{
> > +
> > + struct platform_device *pdev = to_platform_device(dev);
> > + struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
> > +
> > + enable_irq(_dev->irq);
> > +
> > + return 0;
> > +}
> > +#endif
> > #ifdef CONFIG_PM_RUNTIME
> > static int omap_i2c_runtime_suspend(struct device *dev)
> > {
> > @@ -1178,10 +1207,18 @@ static int omap_i2c_runtime_resume(struct device *dev)
> >
> > return 0;
> > }
> > +#endif
> >
> > +#if defined(CONFIG_SUSPEND) || defined(CONFIG_PM_RUNTIME)
>
> #ifdef CONFIG_PM will cover this
>
> > static struct dev_pm_ops omap_i2c_pm_ops = {
> > +#ifdef CONFIG_SUSPEND
>
> again, CONFIG_PM_SLEEP here
>
> > + .suspend_late = omap_i2c_suspend_late,
> > + .resume_early = omap_i2c_resume_early,
> > +#endif
> > +#ifdef CONFIG_PM_RUNTIME
> > .runtime_suspend = omap_i2c_runtime_suspend,
> > .runtime_resume = omap_i2c_runtime_resume,
> > +#endif
> > };
> > #define OMAP_I2C_PM_OPS (&omap_i2c_pm_ops)
> > #else
>
> Kevin
^ permalink raw reply [flat|nested] 3+ messages in thread
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2012-10-05 8:55 [PATCH] i2c: i2c-omap: fix interrupt flood during resume Kalle Jokiniemi
[not found] ` <1349427316-24990-1-git-send-email-kalle.jokiniemi-4y2FMlU5MS8onNqTyK5kxQ@public.gmane.org>
2012-10-05 22:07 ` Kevin Hilman
[not found] ` <87boggmv3j.fsf-1D3HCaltpLuhEniVeURVKkEOCMrvLtNR@public.gmane.org>
2012-10-08 6:21 ` Kalle Jokiniemi
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