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

Imre Deak
2015-11-18T13:28:43Z

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

> ---
>  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)
>  {