[PATCH 1/2] drm: Stop using drm_vblank_count() as the hw frame counter
Rob Clark
robdclark at gmail.com
Thu Oct 1 08:56:11 PDT 2015
On Thu, Oct 1, 2015 at 11:47 AM, Ville Syrjälä
<ville.syrjala at linux.intel.com> wrote:
> On Thu, Oct 01, 2015 at 06:44:22PM +0300, Ville Syrjälä wrote:
>> On Thu, Oct 01, 2015 at 11:25:36AM -0400, Rob Clark wrote:
>> > On Wed, Sep 30, 2015 at 10:14 AM, Ville Syrjälä
>> > <ville.syrjala at linux.intel.com> wrote:
>> > > On Wed, Sep 30, 2015 at 04:08:02PM +0200, Daniel Vetter wrote:
>> > >> On Wed, Sep 30, 2015 at 04:46:48PM +0300, ville.syrjala at linux.intel.com wrote:
>> > >> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> > >> >
>> > >> > drm_vblank_count() returns the software counter. We should not pretend
>> > >> > it's the hw counter since we use the hw counter to figuere out what the
>> > >> > software counter value should be. So instead provide a new function
>> > >> > drm_vblank_no_hw_counter() for drivers that don't have a real hw
>> > >> > counter. The new function simply returns 0, which is about the only
>> > >> > thing it can do.
>> > >>
>> > >> Shouldn't we instead just make the get_vblank_counter hook optional?
>> > >
>> > > Perhaps. But maybe this way would encourage people to go look for a
>> > > hw frame counter in their hardware?
>> >
>> > Well, I guess at this point we have more drm/kms drivers for hw
>> > without hw frame counters.. maybe a helper that guestimates based on
>> > time elapsed since last vbl irq would be useful..
>>
>> That's already being done for the sw counter.
>
> ... assuming you have accurate vbl timestamps that is.
yeah.. the set of drivers supporting drv->get_vblank_timestamp() is
even smaller than the ones supporting drv->get_vblank_counter() ;-)
That all said, I think msm/mdp5 could actually support
->get_vblank_counter(), and I think even ->get_scanout_position() and
therefore ->get_vblank_timestamp().. but afaict mdp4 does not have
any line and frame count registers. And iirc, omap did not.. and I'd
guess a lot of the other small embedded and mobile display controller
blocks out there do not..
BR,
-R
>> >
>> > >> -Daniel
>> > >>
>> > >> >
>> > >> > Cc: Vincent Abriou <vincent.abriou at st.com>
>> > >> > Cc: Thierry Reding <treding at nvidia.com>
>> > >> > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> > >> > ---
>> > >> > drivers/gpu/drm/armada/armada_drv.c | 2 +-
>> > >> > drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c | 2 +-
>> > >> > drivers/gpu/drm/drm_irq.c | 17 +++++++++++++++++
>> > >> > drivers/gpu/drm/exynos/exynos_drm_drv.c | 2 +-
>> > >> > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 2 +-
>> > >> > drivers/gpu/drm/imx/imx-drm-core.c | 2 +-
>> > >> > drivers/gpu/drm/msm/msm_drv.c | 2 +-
>> > >> > drivers/gpu/drm/nouveau/nouveau_drm.c | 2 +-
>> > >> > drivers/gpu/drm/omapdrm/omap_drv.c | 2 +-
>> > >> > drivers/gpu/drm/rcar-du/rcar_du_drv.c | 2 +-
>> > >> > drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 2 +-
>> > >> > drivers/gpu/drm/shmobile/shmob_drm_drv.c | 2 +-
>> > >> > drivers/gpu/drm/sti/sti_drv.c | 2 +-
>> > >> > drivers/gpu/drm/tilcdc/tilcdc_drv.c | 2 +-
>> > >> > include/drm/drmP.h | 1 +
>> > >> > 15 files changed, 31 insertions(+), 13 deletions(-)
>> > >> >
>> > >> > diff --git a/drivers/gpu/drm/armada/armada_drv.c b/drivers/gpu/drm/armada/armada_drv.c
>> > >> > index 225034b..464a13f 100644
>> > >> > --- a/drivers/gpu/drm/armada/armada_drv.c
>> > >> > +++ b/drivers/gpu/drm/armada/armada_drv.c
>> > >> > @@ -300,7 +300,7 @@ static struct drm_driver armada_drm_driver = {
>> > >> > .lastclose = armada_drm_lastclose,
>> > >> > .unload = armada_drm_unload,
>> > >> > .set_busid = drm_platform_set_busid,
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = armada_drm_enable_vblank,
>> > >> > .disable_vblank = armada_drm_disable_vblank,
>> > >> > #ifdef CONFIG_DEBUG_FS
>> > >> > diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
>> > >> > index 8bc62ec..2eb1c66 100644
>> > >> > --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
>> > >> > +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
>> > >> > @@ -697,7 +697,7 @@ static struct drm_driver atmel_hlcdc_dc_driver = {
>> > >> > .irq_preinstall = atmel_hlcdc_dc_irq_uninstall,
>> > >> > .irq_postinstall = atmel_hlcdc_dc_irq_postinstall,
>> > >> > .irq_uninstall = atmel_hlcdc_dc_irq_uninstall,
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = atmel_hlcdc_dc_enable_vblank,
>> > >> > .disable_vblank = atmel_hlcdc_dc_disable_vblank,
>> > >> > .gem_free_object = drm_gem_cma_free_object,
>> > >> > diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
>> > >> > index ed2394e..7d70b7c 100644
>> > >> > --- a/drivers/gpu/drm/drm_irq.c
>> > >> > +++ b/drivers/gpu/drm/drm_irq.c
>> > >> > @@ -1797,3 +1797,20 @@ bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
>> > >> > return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
>> > >> > }
>> > >> > EXPORT_SYMBOL(drm_crtc_handle_vblank);
>> > >> > +
>> > >> > +/**
>> > >> > + * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
>> > >> > + * @dev: DRM device
>> > >> > + * @pipe: CRTC for which to read the counter
>> > >> > + *
>> > >> > + * Drivers can plug this into the .get_vblank_counter() function if
>> > >> > + * there is no useable hardware frame counter available.
>> > >> > + *
>> > >> > + * Returns:
>> > >> > + * 0
>> > >> > + */
>> > >> > +u32 drm_vblank_no_hw_counter(struct drm_device *dev, int pipe)
>> > >> > +{
>> > >> > + return 0;
>> > >> > +}
>> > >> > +EXPORT_SYMBOL(drm_vblank_no_hw_counter);
>> > >> > diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
>> > >> > index f0a5839..fb9cfc5 100644
>> > >> > --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
>> > >> > +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
>> > >> > @@ -447,7 +447,7 @@ static struct drm_driver exynos_drm_driver = {
>> > >> > .lastclose = exynos_drm_lastclose,
>> > >> > .postclose = exynos_drm_postclose,
>> > >> > .set_busid = drm_platform_set_busid,
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = exynos_drm_crtc_enable_vblank,
>> > >> > .disable_vblank = exynos_drm_crtc_disable_vblank,
>> > >> > .gem_free_object = exynos_drm_gem_free_object,
>> > >> > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
>> > >> > index 9a8e2da..1f4e8b9 100644
>> > >> > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
>> > >> > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
>> > >> > @@ -192,7 +192,7 @@ static struct drm_driver fsl_dcu_drm_driver = {
>> > >> > .unload = fsl_dcu_unload,
>> > >> > .preclose = fsl_dcu_drm_preclose,
>> > >> > .irq_handler = fsl_dcu_drm_irq,
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = fsl_dcu_drm_enable_vblank,
>> > >> > .disable_vblank = fsl_dcu_drm_disable_vblank,
>> > >> > .gem_free_object = drm_gem_cma_free_object,
>> > >> > diff --git a/drivers/gpu/drm/imx/imx-drm-core.c b/drivers/gpu/drm/imx/imx-drm-core.c
>> > >> > index 74f505b..18a6642 100644
>> > >> > --- a/drivers/gpu/drm/imx/imx-drm-core.c
>> > >> > +++ b/drivers/gpu/drm/imx/imx-drm-core.c
>> > >> > @@ -487,7 +487,7 @@ static struct drm_driver imx_drm_driver = {
>> > >> > .gem_prime_vmap = drm_gem_cma_prime_vmap,
>> > >> > .gem_prime_vunmap = drm_gem_cma_prime_vunmap,
>> > >> > .gem_prime_mmap = drm_gem_cma_prime_mmap,
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = imx_drm_enable_vblank,
>> > >> > .disable_vblank = imx_drm_disable_vblank,
>> > >> > .ioctls = imx_drm_ioctls,
>> > >> > diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
>> > >> > index 0339c5d..3eba23f 100644
>> > >> > --- a/drivers/gpu/drm/msm/msm_drv.c
>> > >> > +++ b/drivers/gpu/drm/msm/msm_drv.c
>> > >> > @@ -978,7 +978,7 @@ static struct drm_driver msm_driver = {
>> > >> > .irq_preinstall = msm_irq_preinstall,
>> > >> > .irq_postinstall = msm_irq_postinstall,
>> > >> > .irq_uninstall = msm_irq_uninstall,
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = msm_enable_vblank,
>> > >> > .disable_vblank = msm_disable_vblank,
>> > >> > .gem_free_object = msm_gem_free_object,
>> > >> > diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
>> > >> > index ccefb64..2416c7d 100644
>> > >> > --- a/drivers/gpu/drm/nouveau/nouveau_drm.c
>> > >> > +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
>> > >> > @@ -934,7 +934,7 @@ driver_stub = {
>> > >> > .debugfs_cleanup = nouveau_debugfs_takedown,
>> > >> > #endif
>> > >> >
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = nouveau_display_vblank_enable,
>> > >> > .disable_vblank = nouveau_display_vblank_disable,
>> > >> > .get_scanout_position = nouveau_display_scanoutpos,
>> > >> > diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
>> > >> > index d685e23..4d58934 100644
>> > >> > --- a/drivers/gpu/drm/omapdrm/omap_drv.c
>> > >> > +++ b/drivers/gpu/drm/omapdrm/omap_drv.c
>> > >> > @@ -839,7 +839,7 @@ static struct drm_driver omap_drm_driver = {
>> > >> > .preclose = dev_preclose,
>> > >> > .postclose = dev_postclose,
>> > >> > .set_busid = drm_platform_set_busid,
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = omap_irq_enable_vblank,
>> > >> > .disable_vblank = omap_irq_disable_vblank,
>> > >> > #ifdef CONFIG_DEBUG_FS
>> > >> > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
>> > >> > index 780ca11..3608e88 100644
>> > >> > --- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
>> > >> > +++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
>> > >> > @@ -259,7 +259,7 @@ static struct drm_driver rcar_du_driver = {
>> > >> > .preclose = rcar_du_preclose,
>> > >> > .lastclose = rcar_du_lastclose,
>> > >> > .set_busid = drm_platform_set_busid,
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = rcar_du_enable_vblank,
>> > >> > .disable_vblank = rcar_du_disable_vblank,
>> > >> > .gem_free_object = drm_gem_cma_free_object,
>> > >> > diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
>> > >> > index 9a0c291..b468add 100644
>> > >> > --- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
>> > >> > +++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
>> > >> > @@ -277,7 +277,7 @@ static struct drm_driver rockchip_drm_driver = {
>> > >> > .load = rockchip_drm_load,
>> > >> > .unload = rockchip_drm_unload,
>> > >> > .lastclose = rockchip_drm_lastclose,
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = rockchip_drm_crtc_enable_vblank,
>> > >> > .disable_vblank = rockchip_drm_crtc_disable_vblank,
>> > >> > .gem_vm_ops = &rockchip_drm_vm_ops,
>> > >> > diff --git a/drivers/gpu/drm/shmobile/shmob_drm_drv.c b/drivers/gpu/drm/shmobile/shmob_drm_drv.c
>> > >> > index 666321d..108a03b 100644
>> > >> > --- a/drivers/gpu/drm/shmobile/shmob_drm_drv.c
>> > >> > +++ b/drivers/gpu/drm/shmobile/shmob_drm_drv.c
>> > >> > @@ -269,7 +269,7 @@ static struct drm_driver shmob_drm_driver = {
>> > >> > .preclose = shmob_drm_preclose,
>> > >> > .set_busid = drm_platform_set_busid,
>> > >> > .irq_handler = shmob_drm_irq,
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = shmob_drm_enable_vblank,
>> > >> > .disable_vblank = shmob_drm_disable_vblank,
>> > >> > .gem_free_object = drm_gem_cma_free_object,
>> > >> > diff --git a/drivers/gpu/drm/sti/sti_drv.c b/drivers/gpu/drm/sti/sti_drv.c
>> > >> > index 9f85988..f846996 100644
>> > >> > --- a/drivers/gpu/drm/sti/sti_drv.c
>> > >> > +++ b/drivers/gpu/drm/sti/sti_drv.c
>> > >> > @@ -201,7 +201,7 @@ static struct drm_driver sti_driver = {
>> > >> > .dumb_destroy = drm_gem_dumb_destroy,
>> > >> > .fops = &sti_driver_fops,
>> > >> >
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = sti_crtc_enable_vblank,
>> > >> > .disable_vblank = sti_crtc_disable_vblank,
>> > >> >
>> > >> > diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
>> > >> > index 0f283a3..7e0b0c5 100644
>> > >> > --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
>> > >> > +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
>> > >> > @@ -563,7 +563,7 @@ static struct drm_driver tilcdc_driver = {
>> > >> > .irq_preinstall = tilcdc_irq_preinstall,
>> > >> > .irq_postinstall = tilcdc_irq_postinstall,
>> > >> > .irq_uninstall = tilcdc_irq_uninstall,
>> > >> > - .get_vblank_counter = drm_vblank_count,
>> > >> > + .get_vblank_counter = drm_vblank_no_hw_counter,
>> > >> > .enable_vblank = tilcdc_enable_vblank,
>> > >> > .disable_vblank = tilcdc_disable_vblank,
>> > >> > .gem_free_object = drm_gem_cma_free_object,
>> > >> > diff --git a/include/drm/drmP.h b/include/drm/drmP.h
>> > >> > index d0251ac..f563333 100644
>> > >> > --- a/include/drm/drmP.h
>> > >> > +++ b/include/drm/drmP.h
>> > >> > @@ -952,6 +952,7 @@ extern void drm_crtc_vblank_off(struct drm_crtc *crtc);
>> > >> > extern void drm_crtc_vblank_reset(struct drm_crtc *crtc);
>> > >> > extern void drm_crtc_vblank_on(struct drm_crtc *crtc);
>> > >> > extern void drm_vblank_cleanup(struct drm_device *dev);
>> > >> > +extern u32 drm_vblank_no_hw_counter(struct drm_device *dev, int pipe);
>> > >> >
>> > >> > extern int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
>> > >> > unsigned int pipe, int *max_error,
>> > >> > --
>> > >> > 2.4.6
>> > >> >
>> > >> > _______________________________________________
>> > >> > dri-devel mailing list
>> > >> > dri-devel at lists.freedesktop.org
>> > >> > http://lists.freedesktop.org/mailman/listinfo/dri-devel
>> > >>
>> > >> --
>> > >> Daniel Vetter
>> > >> Software Engineer, Intel Corporation
>> > >> http://blog.ffwll.ch
>> > >
>> > > --
>> > > Ville Syrjälä
>> > > Intel OTC
>> > > _______________________________________________
>> > > dri-devel mailing list
>> > > dri-devel at lists.freedesktop.org
>> > > http://lists.freedesktop.org/mailman/listinfo/dri-devel
>>
>> --
>> Ville Syrjälä
>> Intel OTC
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Ville Syrjälä
> Intel OTC
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