From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kalle Jokiniemi Subject: Re: [PATCH v2] ARM: OMAP: i2c: fix interrupt flood during resume Date: Wed, 10 Oct 2012 15:09:09 +0300 Message-ID: <1349870949.17145.7.camel@kj-X230> References: <1349869566-21756-1-git-send-email-kalle.jokiniemi@jollamobile.com> <1349870051.17145.5.camel@kj-X230> Reply-To: kalle.jokiniemi-ieSKYCWCyXoAvxtiuMwx3w@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1349870051.17145.5.camel@kj-X230> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: kalle.jokiniemi-ieSKYCWCyXoAvxtiuMwx3w@public.gmane.org Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, grygorii.strashko-l0cyMroinI0@public.gmane.org, khilman-1D3HCaltpLuhEniVeURVKkEOCMrvLtNR@public.gmane.org, shubhrajyoti-l0cyMroinI0@public.gmane.org List-Id: linux-i2c@vger.kernel.org ke, 2012-10-10 kello 14:54 +0300, Kalle Jokiniemi kirjoitti: > ke, 2012-10-10 kello 14:46 +0300, Kalle Jokiniemi kirjoitti: > > 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. Ugh, forgot to update commit message. Version 3 coming shortly... - Kalle > > > > Issue was detected doing a wake up from autosleep with > > twl4030 power key on N9. Patch tested on N9. > > I did this now on top of latest linux-omap, should apply also to Jean's > staging tree. Let me know if something more is needed. > > - Kalle > > > > > Signed-off-by: Kalle Jokiniemi > > --- > > drivers/i2c/busses/i2c-omap.c | 34 ++++++++++++++++++++++++++++++++++ > > 1 files changed, 34 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > > index a0e49f6..991341b 100644 > > --- a/drivers/i2c/busses/i2c-omap.c > > +++ b/drivers/i2c/busses/i2c-omap.c > > @@ -1132,6 +1132,36 @@ static int __devexit omap_i2c_remove(struct platform_device *pdev) > > } > > > > #ifdef CONFIG_PM > > +#ifdef CONFIG_PM_SLEEP > > +static int omap_i2c_suspend_noirq(struct device *dev) > > +{ > > + > > + struct platform_device *pdev = to_platform_device(dev); > > + struct omap_i2c_dev *_dev = platform_get_drvdata(pdev); > > + > > + /* Disabling irq here to balance the enable in resume_early */ > > + 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); > > + > > + /* > > + * 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 > > + * keep the bus irq disabled until all other irqs have been enabled. > > + */ > > + enable_irq(_dev->irq); > > + > > + return 0; > > +} > > +#endif > > #ifdef CONFIG_PM_RUNTIME > > static int omap_i2c_runtime_suspend(struct device *dev) > > { > > @@ -1183,6 +1213,10 @@ static int omap_i2c_runtime_resume(struct device *dev) > > #endif /* CONFIG_PM_RUNTIME */ > > > > static struct dev_pm_ops omap_i2c_pm_ops = { > > +#ifdef CONFIG_PM_SLEEP > > + .suspend_noirq = omap_i2c_suspend_noirq, > > + .resume_early = omap_i2c_resume_early, > > +#endif > > SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend, > > omap_i2c_runtime_resume, NULL) > > }; > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html