| Message ID | 20170621014457.26587-4-mario.kleiner.de@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 21/06/17 10:44 AM, Mario Kleiner wrote: > With instantaneous high precision vblank timestamping > that updates at leading edge of vblank, a cooked hw > vblank counter which increments at leading edge of > vblank, and reliable page flip execution and completion > at leading edge of vblank, we should meet the requirements > for fast/immediate vblank irq disable/enable. > > Testing on Linux-4.12-rc5 + drm-next on a Radeon R9 380 > Tonga Pro (DCE 10) with timing measurement equipment > indicates this works fine, so allow immediate vblank > disable for power saving. > > For debugging in case of unexpected trouble, booting > with kernel cmdline option drm.vblankoffdelay=0 > (or echo 0 > /sys/module/drm/parameters/vblankoffdelay) > would keep vblank irqs permanently on to approximate old > behavior. > > Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com> > Cc: Alex Deucher <alexander.deucher@amd.com> > Cc: Michel Dänzer <michel.daenzer@amd.com> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c > index 62da6c5..a28f8aa 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c > @@ -220,6 +220,10 @@ int amdgpu_irq_init(struct amdgpu_device *adev) > int r = 0; > > spin_lock_init(&adev->irq.lock); > + > + /* Disable vblank irqs aggressively for power-saving */ > + adev->ddev->vblank_disable_immediate = true; > + > r = drm_vblank_init(adev->ddev, adev->mode_info.num_crtc); > if (r) { > return r; > Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
On Wed, Jun 21, 2017 at 3:22 AM, Michel Dänzer <michel@daenzer.net> wrote: > On 21/06/17 10:44 AM, Mario Kleiner wrote: >> With instantaneous high precision vblank timestamping >> that updates at leading edge of vblank, a cooked hw >> vblank counter which increments at leading edge of >> vblank, and reliable page flip execution and completion >> at leading edge of vblank, we should meet the requirements >> for fast/immediate vblank irq disable/enable. >> >> Testing on Linux-4.12-rc5 + drm-next on a Radeon R9 380 >> Tonga Pro (DCE 10) with timing measurement equipment >> indicates this works fine, so allow immediate vblank >> disable for power saving. >> >> For debugging in case of unexpected trouble, booting >> with kernel cmdline option drm.vblankoffdelay=0 >> (or echo 0 > /sys/module/drm/parameters/vblankoffdelay) >> would keep vblank irqs permanently on to approximate old >> behavior. >> >> Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com> >> Cc: Alex Deucher <alexander.deucher@amd.com> >> Cc: Michel Dänzer <michel.daenzer@amd.com> >> --- >> drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c >> index 62da6c5..a28f8aa 100644 >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c >> @@ -220,6 +220,10 @@ int amdgpu_irq_init(struct amdgpu_device *adev) >> int r = 0; >> >> spin_lock_init(&adev->irq.lock); >> + >> + /* Disable vblank irqs aggressively for power-saving */ >> + adev->ddev->vblank_disable_immediate = true; >> + >> r = drm_vblank_init(adev->ddev, adev->mode_info.num_crtc); >> if (r) { >> return r; >> > > Reviewed-by: Michel Dänzer <michel.daenzer@amd.com> Applied patches 2 and 3. Thanks, Alex > > > -- > Earthling Michel Dänzer | http://www.amd.com > Libre software enthusiast | Mesa and X developer > _______________________________________________ > amd-gfx mailing list > amd-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c index 62da6c5..a28f8aa 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c @@ -220,6 +220,10 @@ int amdgpu_irq_init(struct amdgpu_device *adev) int r = 0; spin_lock_init(&adev->irq.lock); + + /* Disable vblank irqs aggressively for power-saving */ + adev->ddev->vblank_disable_immediate = true; + r = drm_vblank_init(adev->ddev, adev->mode_info.num_crtc); if (r) { return r;
With instantaneous high precision vblank timestamping that updates at leading edge of vblank, a cooked hw vblank counter which increments at leading edge of vblank, and reliable page flip execution and completion at leading edge of vblank, we should meet the requirements for fast/immediate vblank irq disable/enable. Testing on Linux-4.12-rc5 + drm-next on a Radeon R9 380 Tonga Pro (DCE 10) with timing measurement equipment indicates this works fine, so allow immediate vblank disable for power saving. For debugging in case of unexpected trouble, booting with kernel cmdline option drm.vblankoffdelay=0 (or echo 0 > /sys/module/drm/parameters/vblankoffdelay) would keep vblank irqs permanently on to approximate old behavior. Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Michel Dänzer <michel.daenzer@amd.com> --- drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 4 ++++ 1 file changed, 4 insertions(+)