On Wed, Apr 20, 2022 at 10:54 PM Quan, Evan <Evan.Quan@xxxxxxx> wrote:
>
> [AMD Official Use Only]
>
>
>
> > -----Original Message-----
> > From: amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Alex
> > Deucher
> > Sent: Thursday, April 14, 2022 4:15 AM
> > To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> > Cc: Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Michele Ballabio
> > <ballabio.m@xxxxxxxxx>
> > Subject: [PATCH] drm/amdgpu: don't runtime suspend if there are displays
> > attached (v2)
> >
> > We normally runtime suspend when there are displays attached if they
> > are in the DPMS off state, however, if something wakes the GPU
> > we send a hotplug event on resume (in case any displays were connected
> > while the GPU was in suspend) which can cause userspace to light
> > up the displays again soon after they were turned off.
> >
> > Prior to
> > commit 087451f372bf76 ("drm/amdgpu: use generic fb helpers instead of
> > setting up AMD own's."),
> > the driver took a runtime pm reference when the fbdev emulation was
> > enabled because we didn't implement proper shadowing support for
> > vram access when the device was off so the device never runtime
> > suspended when there was a console bound. Once that commit landed,
> > we now utilize the core fb helper implementation which properly
> > handles the emulation, so runtime pm now suspends in cases where it did
> > not before. Ultimately, we need to sort out why runtime suspend in not
> > working in this case for some users, but this should restore similar
> > behavior to before.
> >
> > v2: move check into runtime_suspend
> >
> > Fixes: 087451f372bf76 ("drm/amdgpu: use generic fb helpers instead of
> > setting up AMD own's.")
> > Tested-by: Michele Ballabio <ballabio.m@xxxxxxxxx>
> > Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
> > ---
> > drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 107 ++++++++++++++++---
> > -----
> > 1 file changed, 72 insertions(+), 35 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > index 4efaa183abcd..97a1aa02d76e 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > @@ -2395,6 +2395,71 @@ static int amdgpu_pmops_restore(struct device
> > *dev)
> > return amdgpu_device_resume(drm_dev, true);
> > }
> >
> > +static int amdgpu_runtime_idle_check_display(struct device *dev)
> > +{
> > + struct pci_dev *pdev = to_pci_dev(dev);
> > + struct drm_device *drm_dev = pci_get_drvdata(pdev);
> > + struct amdgpu_device *adev = drm_to_adev(drm_dev);
> > +
> > + if (adev->mode_info.num_crtc) {
> > + struct drm_connector *list_connector;
> > + struct drm_connector_list_iter iter;
> > + int ret = 0;
> > +
> > + /* XXX: Return busy if any displays are connected to avoid
> > + * possible display wake ups after runtime resume due to
> > + * hotplug events in case any displays were connected while
> > + * the GPU was in suspend. Remove this once that is fixed.
> > + */
> > + mutex_lock(&drm_dev->mode_config.mutex);
> > + drm_connector_list_iter_begin(drm_dev, &iter);
> > + drm_for_each_connector_iter(list_connector, &iter) {
> > + if (list_connector->status ==
> > connector_status_connected) {
> > + ret = -EBUSY;
> > + break;
> > + }
> > + }
> > + drm_connector_list_iter_end(&iter);
> > + mutex_unlock(&drm_dev->mode_config.mutex);
> > +
> > + if (ret)
> > + return ret;
> > +
> > + if (amdgpu_device_has_dc_support(adev)) {
> > + struct drm_crtc *crtc;
> > +
> > + drm_for_each_crtc(crtc, drm_dev) {
> > + drm_modeset_lock(&crtc->mutex, NULL);
> > + if (crtc->state->active)
> > + ret = -EBUSY;
> > + drm_modeset_unlock(&crtc->mutex);
> > + if (ret < 0)
> > + break;
> > + }
> > + } else {
> > + mutex_lock(&drm_dev->mode_config.mutex);
> > + drm_modeset_lock(&drm_dev-
> > >mode_config.connection_mutex, NULL);
> > +
> > + drm_connector_list_iter_begin(drm_dev, &iter);
> > + drm_for_each_connector_iter(list_connector, &iter)
> > {
> > + if (list_connector->dpms ==
> > DRM_MODE_DPMS_ON) {
> > + ret = -EBUSY;
> > + break;
> > + }
> > + }
> > +
> > + drm_connector_list_iter_end(&iter);
> > +
> > + drm_modeset_unlock(&drm_dev-
> > >mode_config.connection_mutex);
> > + mutex_unlock(&drm_dev->mode_config.mutex);
> > + }
> > + if (ret)
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > static int amdgpu_pmops_runtime_suspend(struct device *dev)
> > {
> > struct pci_dev *pdev = to_pci_dev(dev);
> > @@ -2407,6 +2472,10 @@ static int
> > amdgpu_pmops_runtime_suspend(struct device *dev)
> > return -EBUSY;
> > }
> >
> > + ret = amdgpu_runtime_idle_check_display(dev);
> > + if (ret)
> > + return ret;
> > +
> > /* wait for all rings to drain before suspending */
> > for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
> > struct amdgpu_ring *ring = adev->rings[i];
> > @@ -2516,41 +2585,9 @@ static int amdgpu_pmops_runtime_idle(struct
> > device *dev)
> > return -EBUSY;
> > }
> >
> > - if (amdgpu_device_has_dc_support(adev)) {
> > - struct drm_crtc *crtc;
> > -
> > - drm_for_each_crtc(crtc, drm_dev) {
> > - drm_modeset_lock(&crtc->mutex, NULL);
> > - if (crtc->state->active)
> > - ret = -EBUSY;
> > - drm_modeset_unlock(&crtc->mutex);
> > - if (ret < 0)
> > - break;
> > - }
> > -
> > - } else {
> > - struct drm_connector *list_connector;
> > - struct drm_connector_list_iter iter;
> > -
> > - mutex_lock(&drm_dev->mode_config.mutex);
> > - drm_modeset_lock(&drm_dev-
> > >mode_config.connection_mutex, NULL);
> > -
> > - drm_connector_list_iter_begin(drm_dev, &iter);
> > - drm_for_each_connector_iter(list_connector, &iter) {
> > - if (list_connector->dpms == DRM_MODE_DPMS_ON)
> > {
> > - ret = -EBUSY;
> > - break;
> > - }
> > - }
> > -
> > - drm_connector_list_iter_end(&iter);
> > -
> > - drm_modeset_unlock(&drm_dev-
> > >mode_config.connection_mutex);
> > - mutex_unlock(&drm_dev->mode_config.mutex);
> > - }
> > -
> > - if (ret == -EBUSY)
> > - DRM_DEBUG_DRIVER("failing to power off - crtc active\n");
> > + ret = amdgpu_runtime_idle_check_display(dev);
> > + if (ret)
> > + return ret;
> [Quan, Evan] Previously, the following actions(pm_runtime_mark_last_busy/pm_runtime_autosuspend) will be still performed even if ret is set as EBUSY.
> But with the new changes, it will abort directly without the following actions performed.
> Is that expected? Will that make any logical change?
Good point. I'll fix that up.
Alex
>
> BR
> Evan
> >
> > pm_runtime_mark_last_busy(dev);
> > pm_runtime_autosuspend(dev);
> > --
> > 2.35.1
