Messages in this thread Patch in this message | | | From | Chen Yu <> | Subject | [PATCH] PM / sysfs: Expose suspend resume driver flags in sysfs | Date | Thu, 22 Oct 2020 11:23:24 +0800 |
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Currently there are 4 driver flags to control system suspend/resume behavior: DPM_FLAG_NO_DIRECT_COMPLETE, DPM_FLAG_SMART_PREPARE, DPM_FLAG_SMART_SUSPEND and DPM_FLAG_MAY_SKIP_RESUME. Make these flags visible in sysfs as read-only to get a brief understanding of the expected behavior of each device during suspend/resume, so as to facilitate suspend/resume debugging/tuning.
For example: /sys/devices/pci0000:00/0000:00:15.1/power/driver_flags:4 (DPM_FLAG_SMART_SUSPEND)
/sys/devices/pci0000:00/0000:00:07.3/power/driver_flags:5 (DPM_FLAG_NO_DIRECT_COMPLETE | DPM_FLAG_SMART_SUSPEND)
Acked-by: Len Brown <len.brown@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> --- drivers/base/power/sysfs.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-)
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c index a1474fb67db9..48313a1040a5 100644 --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -607,6 +607,13 @@ static ssize_t async_store(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RW(async); +static ssize_t driver_flags_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%x\n", dev->power.driver_flags); +} +static DEVICE_ATTR_RO(driver_flags); + #endif /* CONFIG_PM_SLEEP */ #endif /* CONFIG_PM_ADVANCED_DEBUG */ @@ -691,6 +698,20 @@ static const struct attribute_group pm_qos_flags_attr_group = { .attrs = pm_qos_flags_attrs, }; +static struct attribute *pm_driver_flags_attrs[] = { +#ifdef CONFIG_PM_ADVANCED_DEBUG +#ifdef CONFIG_PM_SLEEP + &dev_attr_driver_flags.attr, +#endif +#endif + NULL, +}; + +static const struct attribute_group pm_driver_flags_attr_group = { + .name = power_group_name, + .attrs = pm_driver_flags_attrs, +}; + int dpm_sysfs_add(struct device *dev) { int rc; @@ -719,11 +740,17 @@ int dpm_sysfs_add(struct device *dev) if (rc) goto err_wakeup; } - rc = pm_wakeup_source_sysfs_add(dev); + rc = sysfs_merge_group(&dev->kobj, &pm_driver_flags_attr_group); if (rc) goto err_latency; + + rc = pm_wakeup_source_sysfs_add(dev); + if (rc) + goto err_flags; return 0; + err_flags: + sysfs_unmerge_group(&dev->kobj, &pm_driver_flags_attr_group); err_latency: sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group); err_wakeup: -- 2.17.1
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