| Message ID | 20170427160231.13337-2-ville.syrjala@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 27 Apr 2017 18:02:20 +0200, ville.syrjala@linux.intel.com wrote: > > From: Ville Syrjälä <ville.syrjala@linux.intel.com> > > Not calling pm_runtime_enable() means that runtime PM can't be > enabled at all via sysfs. So we definitely need to call it > from somewhere. > > Calling it from the driver seems like a bad idea because it > would have to be paired with a pm_runtime_disable() at driver > unload time, otherwise the core gets upset. Also if there's > no LPE audio driver loaded then we couldn't runtime suspend > i915 either. > > So it looks like a better plan is to call it from i915 when > we register the platform device. That seems to match how > pci generally does things. I cargo culted the > pm_runtime_forbid() and pm_runtime_set_active() calls from > pci as well. > > The exposed runtime PM API is massive an thorougly misleading, so > I don't actually know if this is how you're supposed to use the API > or not. But it seems to work. I can now runtime suspend i915 again > with or without the LPE audio driver loaded, and reloading the > LPE audio driver also seems to work. > > Note that powertop won't auto-tune runtime PM for platform devices, > which is a little annoying. So I'm not sure that leaving runtime > PM in "on" mode by default is the best choice here. But I've left > it like that for now at least. The reason I didn't proactively turn on the runtime PM was that it often caused a few seconds of pause to the A/V receivers before actually starting playing. There is a planned feature to keep sending the silent stream even after stopping the stream, but it's not implemented yet. > Also remove the comment about there not being much benefit from > LPE audio runtime PM. Not allowing runtime PM blocks i915 runtime > PM, which will also block s0ix, and that could have a measurable > impact on power consumption. > > Cc: Takashi Iwai <tiwai@suse.de> > Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> > Fixes: 0b6b524f3915 ("ALSA: x86: Don't enable runtime PM as default") > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Takashi Iwai <tiwai@suse.de> IMO, this should be tagged with Cc to stable. thanks, Takashi
diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c b/drivers/gpu/drm/i915/intel_lpe_audio.c index 25d8e76489e4..668f00480d97 100644 --- a/drivers/gpu/drm/i915/intel_lpe_audio.c +++ b/drivers/gpu/drm/i915/intel_lpe_audio.c @@ -63,6 +63,7 @@ #include <linux/acpi.h> #include <linux/device.h> #include <linux/pci.h> +#include <linux/pm_runtime.h> #include "i915_drv.h" #include <linux/delay.h> @@ -121,6 +122,10 @@ lpe_audio_platdev_create(struct drm_i915_private *dev_priv) kfree(rsc); + pm_runtime_forbid(&platdev->dev); + pm_runtime_set_active(&platdev->dev); + pm_runtime_enable(&platdev->dev); + return platdev; err: diff --git a/sound/x86/intel_hdmi_audio.c b/sound/x86/intel_hdmi_audio.c index c505b019e09c..bfac6f21ae5e 100644 --- a/sound/x86/intel_hdmi_audio.c +++ b/sound/x86/intel_hdmi_audio.c @@ -1809,10 +1809,6 @@ static int hdmi_lpe_audio_probe(struct platform_device *pdev) pdata->notify_pending = false; spin_unlock_irq(&pdata->lpe_audio_slock); - /* runtime PM isn't enabled as default, since it won't save much on - * BYT/CHT devices; user who want the runtime PM should adjust the - * power/ontrol and power/autosuspend_delay_ms sysfs entries instead - */ pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_mark_last_busy(&pdev->dev); pm_runtime_set_active(&pdev->dev);