| Message ID | 20201124130742.10986-1-yung-chuan.liao@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | soundwire: master: use pm_runtime_set_active() on add | expand |
On 26-11-20, 03:11, Liao, Bard wrote: > > -----Original Message----- > > From: Vinod Koul <vkoul@kernel.org> > > Sent: Wednesday, November 25, 2020 1:05 PM > > To: Bard Liao <yung-chuan.liao@linux.intel.com> > > Cc: alsa-devel@alsa-project.org; linux-kernel@vger.kernel.org; > > gregkh@linuxfoundation.org; jank@cadence.com; > > srinivas.kandagatla@linaro.org; rander.wang@linux.intel.com; > > ranjani.sridharan@linux.intel.com; hui.wang@canonical.com; pierre- > > louis.bossart@linux.intel.com; Kale, Sanyog R <sanyog.r.kale@intel.com>; Lin, > > Mengdong <mengdong.lin@intel.com>; Liao, Bard <bard.liao@intel.com> > > Subject: Re: [PATCH] soundwire: master: use pm_runtime_set_active() on > > add > > > > On 24-11-20, 21:07, Bard Liao wrote: > > > From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> > > > > > > The 'master' device acts as a glue layer used during bus > > > initialization only, and it needs to be 'transparent' for pm_runtime > > > management. Its behavior should be that it becomes active when one of > > > its children becomes active, and suspends when all of its children are > > > suspended. > > > > > > In our tests on Intel platforms, we routinely see these sort of > > > warnings on the initial boot: > > > > > > [ 21.447345] rt715 sdw:3:25d:715:0: runtime PM trying to activate > > > child device sdw:3:25d:715:0 but parent (sdw-master-3) is not active > > > > > > This is root-caused to a missing setup to make the device 'active' on > > > probe. Since we don't want the device to remain active forever after > > > the probe, the autosuspend configuration is also enabled at the end of > > > the probe - the device will actually autosuspend only in the case > > > where there are no devices physically attached. In practice, the > > > master device will suspend when all its children are no longer active. > > > > > > Fixes: bd84256e86ecf ('soundwire: master: enable pm runtime') > > > Signed-off-by: Pierre-Louis Bossart > > > <pierre-louis.bossart@linux.intel.com> > > > Reviewed-by: Rander Wang <rander.wang@linux.intel.com> > > > Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> > > > --- > > > drivers/soundwire/master.c | 14 ++++++++++++++ > > > 1 file changed, 14 insertions(+) > > > > > > diff --git a/drivers/soundwire/master.c b/drivers/soundwire/master.c > > > index 3488bb824e84..9b05c9e25ebe 100644 > > > --- a/drivers/soundwire/master.c > > > +++ b/drivers/soundwire/master.c > > > @@ -8,6 +8,15 @@ > > > #include <linux/soundwire/sdw_type.h> #include "bus.h" > > > > > > +/* > > > + * The 3s value for autosuspend will only be used if there are no > > > + * devices physically attached on a bus segment. In practice enabling > > > + * the bus operation will result in children devices become active > > > +and > > > + * the master device will only suspend when all its children are no > > > + * longer active. > > > + */ > > > +#define SDW_MASTER_SUSPEND_DELAY_MS 3000 > > > + > > > /* > > > * The sysfs for properties reflects the MIPI description as given > > > * in the MIPI DisCo spec > > > @@ -154,7 +163,12 @@ int sdw_master_device_add(struct sdw_bus *bus, > > struct device *parent, > > > bus->dev = &md->dev; > > > bus->md = md; > > > > > > + pm_runtime_set_autosuspend_delay(&bus->md->dev, > > SDW_MASTER_SUSPEND_DELAY_MS); > > > + pm_runtime_use_autosuspend(&bus->md->dev); > > > + pm_runtime_mark_last_busy(&bus->md->dev); > > > + pm_runtime_set_active(&bus->md->dev); > > > pm_runtime_enable(&bus->md->dev); > > > + pm_runtime_idle(&bus->md->dev); > > > > I understand that this needs to be done somewhere but is the core the right > > place. In intel case it maybe a dummy device but other controllers are real > > devices and may not support pm. > > > > I think better idea would be to do this in respective driver.. that way it > > would be an opt-in for device supporting pm. > > Should it be put in the same place as pm_runtime_enable? > IMHO, pm_runtime_enable is in the core already and it seems to be harmless > for devices which don't support pm. And pm can still be optional on md's > parent device. For intel case yes, but world is not only intel, there are md which do not have a parent like sof. they are real sdw controller devices
On 26-11-20, 09:52, Vinod Koul wrote: > > > > @@ -154,7 +163,12 @@ int sdw_master_device_add(struct sdw_bus *bus, > > > struct device *parent, > > > > bus->dev = &md->dev; > > > > bus->md = md; > > > > > > > > + pm_runtime_set_autosuspend_delay(&bus->md->dev, > > > SDW_MASTER_SUSPEND_DELAY_MS); > > > > + pm_runtime_use_autosuspend(&bus->md->dev); > > > > + pm_runtime_mark_last_busy(&bus->md->dev); > > > > + pm_runtime_set_active(&bus->md->dev); > > > > pm_runtime_enable(&bus->md->dev); > > > > + pm_runtime_idle(&bus->md->dev); > > > > > > I understand that this needs to be done somewhere but is the core the right > > > place. In intel case it maybe a dummy device but other controllers are real > > > devices and may not support pm. > > > > > > I think better idea would be to do this in respective driver.. that way it > > > would be an opt-in for device supporting pm. > > > > Should it be put in the same place as pm_runtime_enable? > > IMHO, pm_runtime_enable is in the core already and it seems to be harmless > > for devices which don't support pm. And pm can still be optional on md's > > parent device. > > For intel case yes, but world is not only intel, there are md which do > not have a parent like sof. they are real sdw controller devices Sorry I confused md with real master device ;-) I guess this patch should be okay then.. As the real parent will control. Thanks
On 24-11-20, 21:07, Bard Liao wrote: > From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> > > The 'master' device acts as a glue layer used during bus > initialization only, and it needs to be 'transparent' for pm_runtime > management. Its behavior should be that it becomes active when one of > its children becomes active, and suspends when all of its children are > suspended. > > In our tests on Intel platforms, we routinely see these sort of > warnings on the initial boot: > > [ 21.447345] rt715 sdw:3:25d:715:0: runtime PM trying to activate > child device sdw:3:25d:715:0 but parent (sdw-master-3) is not active > > This is root-caused to a missing setup to make the device 'active' on > probe. Since we don't want the device to remain active forever after > the probe, the autosuspend configuration is also enabled at the end of > the probe - the device will actually autosuspend only in the case > where there are no devices physically attached. In practice, the > master device will suspend when all its children are no longer active. Applied, thanks
diff --git a/drivers/soundwire/master.c b/drivers/soundwire/master.c index 3488bb824e84..9b05c9e25ebe 100644 --- a/drivers/soundwire/master.c +++ b/drivers/soundwire/master.c @@ -8,6 +8,15 @@ #include <linux/soundwire/sdw_type.h> #include "bus.h" +/* + * The 3s value for autosuspend will only be used if there are no + * devices physically attached on a bus segment. In practice enabling + * the bus operation will result in children devices become active and + * the master device will only suspend when all its children are no + * longer active. + */ +#define SDW_MASTER_SUSPEND_DELAY_MS 3000 + /* * The sysfs for properties reflects the MIPI description as given * in the MIPI DisCo spec @@ -154,7 +163,12 @@ int sdw_master_device_add(struct sdw_bus *bus, struct device *parent, bus->dev = &md->dev; bus->md = md; + pm_runtime_set_autosuspend_delay(&bus->md->dev, SDW_MASTER_SUSPEND_DELAY_MS); + pm_runtime_use_autosuspend(&bus->md->dev); + pm_runtime_mark_last_busy(&bus->md->dev); + pm_runtime_set_active(&bus->md->dev); pm_runtime_enable(&bus->md->dev); + pm_runtime_idle(&bus->md->dev); device_register_err: return ret; }