Re: [PATCH v2] PCI / PM: tune down RPM suspend error message with EBUSY and EAGAIN retval

Daniel Vetter
2015-11-18T14:19:47Z

On Wed, Nov 18, 2015 at 03:28:38PM +0200, Imre Deak wrote:
> On ke, 2015-11-18 at 12:56 +0200, Imre Deak wrote:
> > The runtime PM core doesn't treat EBUSY and EAGAIN retvals from the driver
> > suspend hooks as errors, but they still show up as errors in dmesg. Tune
> > them down.
> >
> > One problem caused by this was noticed by Daniel: the i915 driver
> > returns EAGAIN to signal a temporary failure to suspend and as a request
> > towards the RPM core for scheduling a suspend again. This is a normal
> > event, but the resulting error message flags a breakage during the
> > driver's automated testing which parses dmesg and picks up the error.
> >
> > v2:
> > - fix compile breake when CONFIG_PM_SLEEP=n (0-day builder)
> >
> > Reported-by: Daniel Vetter <daniel.vetter@intel.com>
> > Signed-off-by: Imre Deak <imre.deak@intel.com>
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92992

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Rafael, can you please pick this up for 4.4? The spurious KERN_ERR noise
in dmesg is causing a lot fo spurious fail in our (very recently put into
place) i915 CI system.

Thanks, Daniel

>
> > ---
> >  drivers/base/power/main.c |  7 +++++--
> >  drivers/pci/pci-driver.c  |  2 +-
> >  include/linux/pm.h        | 11 +++++++++--
> >  3 files changed, 15 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
> > index 1710c26..39d2090 100644
> > --- a/drivers/base/power/main.c
> > +++ b/drivers/base/power/main.c
> > @@ -1679,9 +1679,12 @@ int dpm_suspend_start(pm_message_t state)
> >  }
> >  EXPORT_SYMBOL_GPL(dpm_suspend_start);
> >
> > -void __suspend_report_result(const char *function, void *fn, int ret)
> > +void __suspend_report_result(const char *function, void *fn, int ret,
> > +      bool runtime_pm)
> >  {
> > - if (ret)
> > + if (runtime_pm && (ret == -EBUSY || ret == -EAGAIN))
> > + printk(KERN_DEBUG "%s(): %pF returns %d\n", function, fn, ret);
> > + else if (ret)
> >   printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
> >  }
> >  EXPORT_SYMBOL_GPL(__suspend_report_result);
> > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> > index 108a311..9569572 100644
> > --- a/drivers/pci/pci-driver.c
> > +++ b/drivers/pci/pci-driver.c
> > @@ -1142,7 +1142,7 @@ static int pci_pm_runtime_suspend(struct device *dev)
> >   pci_dev->state_saved = false;
> >   pci_dev->no_d3cold = false;
> >   error = pm->runtime_suspend(dev);
> > - suspend_report_result(pm->runtime_suspend, error);
> > + rpm_suspend_report_result(pm->runtime_suspend, error);
> >   if (error)
> >   return error;
> >   if (!pci_dev->d3cold_allowed)
> > diff --git a/include/linux/pm.h b/include/linux/pm.h
> > index 35d599e..54f37e3 100644
> > --- a/include/linux/pm.h
> > +++ b/include/linux/pm.h
> > @@ -702,11 +702,17 @@ extern int dpm_suspend_late(pm_message_t state);
> >  extern int dpm_suspend(pm_message_t state);
> >  extern int dpm_prepare(pm_message_t state);
> >
> > -extern void __suspend_report_result(const char *function, void *fn, int ret);
> > +extern void __suspend_report_result(const char *function, void *fn, int ret,
> > +     bool runtime_pm);
> >
> >  #define suspend_report_result(fn, ret) \
> >   do { \
> > - __suspend_report_result(__func__, fn, ret); \
> > + __suspend_report_result(__func__, fn, ret, false); \
> > + } while (0)
> > +
> > +#define rpm_suspend_report_result(fn, ret) \
> > + do { \
> > + __suspend_report_result(__func__, fn, ret, true); \
> >   } while (0)
> >
> >  extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
> > @@ -744,6 +750,7 @@ static inline int dpm_suspend_start(pm_message_t state)
> >  }
> >
> >  #define suspend_report_result(fn, ret) do {} while (0)
> > +#define rpm_suspend_report_result(fn, ret) do {} while (0)
> >
> >  static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
> >  {

--
Daniel Vetter
Software Engineer, Intel Corporation