Re: [Intel-gfx] [PATCH 12/26] drm/atomic-helper: Massage swap_state signature somewhat

Daniel Vetter
2016-05-30T15:09:07Z

On Mon, May 30, 2016 at 03:08:39PM +0200, Maarten Lankhorst wrote:
> Op 29-05-16 om 20:35 schreef Daniel Vetter:
> > - dev is redundant, we have state->atomic
> > - add stall parameter, which must be set when swapping needs to stall
> > for preceeding commits to stop looking at ->state pointers. Currently
> > all drivers need this to be, just prep work for a glorious future.
> I have to disagree, if you want to stall it should be done in a separate helper before swapping state.
> That function should also have the ability to fail, since we haven't called swap_state yet. :)
>
> Maybe with nonblock as parameter, so it could fail with -EBUSY if it would stall, and -EINTR if interrupted?

This is not the stalling you're thinking of. The EBUSY check is in
drm_atomic_helper_setup_commit (and as such entirely optional).

And if you don't ever use the nonblocking helpers, no struct
drm_crtc_commit will ever show up in crtc->commit_list, which means this
here also doesn't do anything.

This stall here is just to make sure that the previous commit doesn't get
confused because we've ripped out crtc/plane/connector->state from
underneath it. And as soon as we add previous_state pointers to
drm_atomic_state and wire it up through all the hooks we can set
stall=false here, since then pipelining with a queue depth > 1 is
possible.
-Daniel

> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > ---
> > drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c | 2 +-
> > drivers/gpu/drm/drm_atomic_helper.c | 8 ++++----
> > drivers/gpu/drm/exynos/exynos_drm_drv.c | 2 +-
> > drivers/gpu/drm/i915/intel_display.c | 2 +-
> > drivers/gpu/drm/mediatek/mtk_drm_drv.c | 2 +-
> > drivers/gpu/drm/msm/msm_atomic.c | 2 +-
> > drivers/gpu/drm/omapdrm/omap_drv.c | 2 +-
> > drivers/gpu/drm/rcar-du/rcar_du_kms.c | 2 +-
> > drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 2 +-
> > drivers/gpu/drm/sti/sti_drv.c | 2 +-
> > drivers/gpu/drm/tegra/drm.c | 2 +-
> > drivers/gpu/drm/vc4/vc4_kms.c | 2 +-
> > include/drm/drm_atomic_helper.h | 4 ++--
> > 13 files changed, 17 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
> > index 6485fa5bee8b..9ecf16c7911d 100644
> > --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
> > +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
> > @@ -519,7 +519,7 @@ static int atmel_hlcdc_dc_atomic_commit(struct drm_device *dev,
> > }
> >
> > /* Swap the state, this is the point of no return. */
> > - drm_atomic_helper_swap_state(dev, state);
> > + drm_atomic_helper_swap_state(state, true);
> >
> > if (async)
> > queue_work(dc->wq, &commit->work);
> > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> > index 5298eb668ca7..fecbb52cbb85 100644
> > --- a/drivers/gpu/drm/drm_atomic_helper.c
> > +++ b/drivers/gpu/drm/drm_atomic_helper.c
> > @@ -1160,7 +1160,7 @@ int drm_atomic_helper_commit(struct drm_device *dev,
> > * the software side now.
> > */
> >
> > - drm_atomic_helper_swap_state(dev, state);
> > + drm_atomic_helper_swap_state(state, true);
> >
> > /*
> > * Everything below can be run asynchronously without the need to grab
> > @@ -1531,8 +1531,8 @@ EXPORT_SYMBOL(drm_atomic_helper_cleanup_planes);
> >
> > /**
> > * drm_atomic_helper_swap_state - store atomic state into current sw state
> > - * @dev: DRM device
> > * @state: atomic state
> > + * @stall: stall for proceeding commits
> > *
> > * This function stores the atomic state into the current state pointers in all
> > * driver objects. It should be called after all failing steps have been done
> > @@ -1554,8 +1554,8 @@ EXPORT_SYMBOL(drm_atomic_helper_cleanup_planes);
> > * 5. Call drm_atomic_helper_cleanup_planes() with @state, which since step 3
> > * contains the old state. Also do any other cleanup required with that state.
> > */
> > -void drm_atomic_helper_swap_state(struct drm_device *dev,
> > - struct drm_atomic_state *state)
> > +void drm_atomic_helper_swap_state(struct drm_atomic_state *state,
> > + bool stall)
> > {
> > int i;
> > struct drm_connector *connector;
> > diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> > index cabc5fd0246d..deba76982358 100644
> > --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
> > +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> > @@ -299,7 +299,7 @@ int exynos_atomic_commit(struct drm_device *dev, struct drm_atomic_state *state,
> > priv->pending |= commit->crtcs;
> > spin_unlock(&priv->lock);
> >
> > - drm_atomic_helper_swap_state(dev, state);
> > + drm_atomic_helper_swap_state(state, true);
> >
> > if (nonblock)
> > schedule_work(&commit->work);
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index 9ccd76699f48..d32274071393 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -13660,7 +13660,7 @@ static int intel_atomic_commit(struct drm_device *dev,
> > return ret;
> > }
> >
> > - drm_atomic_helper_swap_state(dev, state);
> > + drm_atomic_helper_swap_state(state, true);
> > dev_priv->wm.distrust_bios_wm = false;
> > dev_priv->wm.skl_results = intel_state->wm_results;
> > intel_shared_dpll_commit(state);
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> > index 06a417b2f91e..c33bf98c5d5e 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> > @@ -91,7 +91,7 @@ static int mtk_atomic_commit(struct drm_device *drm,
> > mutex_lock(&private->commit.lock);
> > flush_work(&private->commit.work);
> >
> > - drm_atomic_helper_swap_state(drm, state);
> > + drm_atomic_helper_swap_state(state, true);
> >
> > if (async)
> > mtk_atomic_schedule(private, state);
> > diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
> > index 9c0e4261dbba..d02bd6a50e90 100644
> > --- a/drivers/gpu/drm/msm/msm_atomic.c
> > +++ b/drivers/gpu/drm/msm/msm_atomic.c
> > @@ -238,7 +238,7 @@ int msm_atomic_commit(struct drm_device *dev,
> > * the software side now.
> > */
> >
> > - drm_atomic_helper_swap_state(dev, state);
> > + drm_atomic_helper_swap_state(state, true);
> >
> > /*
> > * Everything below can be run asynchronously without the need to grab
> > diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
> > index d86f5479345b..5d8377aad639 100644
> > --- a/drivers/gpu/drm/omapdrm/omap_drv.c
> > +++ b/drivers/gpu/drm/omapdrm/omap_drv.c
> > @@ -175,7 +175,7 @@ static int omap_atomic_commit(struct drm_device *dev,
> > spin_unlock(&priv->commit.lock);
> >
> > /* Swap the state, this is the point of no return. */
> > - drm_atomic_helper_swap_state(dev, state);
> > + drm_atomic_helper_swap_state(state, true);
> >
> > if (nonblock)
> > schedule_work(&commit->work);
> > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
> > index f315c55c1f65..3d04a506cf33 100644
> > --- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
> > +++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
> > @@ -327,7 +327,7 @@ static int rcar_du_atomic_commit(struct drm_device *dev,
> > }
> >
> > /* Swap the state, this is the point of no return. */
> > - drm_atomic_helper_swap_state(dev, state);
> > + drm_atomic_helper_swap_state(state, true);
> >
> > if (nonblock)
> > schedule_work(&commit->work);
> > diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> > index 03913b483506..5ea141dfae5b 100644
> > --- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> > +++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> > @@ -290,7 +290,7 @@ int rockchip_drm_atomic_commit(struct drm_device *dev,
> > mutex_lock(&commit->lock);
> > flush_work(&commit->work);
> >
> > - drm_atomic_helper_swap_state(dev, state);
> > + drm_atomic_helper_swap_state(state, true);
> >
> > commit->dev = dev;
> > commit->state = state;
> > diff --git a/drivers/gpu/drm/sti/sti_drv.c b/drivers/gpu/drm/sti/sti_drv.c
> > index b440617a7019..dd2c400c4a46 100644
> > --- a/drivers/gpu/drm/sti/sti_drv.c
> > +++ b/drivers/gpu/drm/sti/sti_drv.c
> > @@ -215,7 +215,7 @@ static int sti_atomic_commit(struct drm_device *drm,
> > * the software side now.
> > */
> >
> > - drm_atomic_helper_swap_state(drm, state);
> > + drm_atomic_helper_swap_state(state, true);
> >
> > if (nonblock)
> > sti_atomic_schedule(private, state);
> > diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
> > index b59c3bf0df44..a177a42a9849 100644
> > --- a/drivers/gpu/drm/tegra/drm.c
> > +++ b/drivers/gpu/drm/tegra/drm.c
> > @@ -93,7 +93,7 @@ static int tegra_atomic_commit(struct drm_device *drm,
> > * the software side now.
> > */
> >
> > - drm_atomic_helper_swap_state(drm, state);
> > + drm_atomic_helper_swap_state(state, true);
> >
> > if (nonblock)
> > tegra_atomic_schedule(tegra, state);
> > diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
> > index 39c0b2048bfd..8f4d5ffc32be 100644
> > --- a/drivers/gpu/drm/vc4/vc4_kms.c
> > +++ b/drivers/gpu/drm/vc4/vc4_kms.c
> > @@ -148,7 +148,7 @@ static int vc4_atomic_commit(struct drm_device *dev,
> > * the software side now.
> > */
> >
> > - drm_atomic_helper_swap_state(dev, state);
> > + drm_atomic_helper_swap_state(state, true);
> >
> > /*
> > * Everything below can be run asynchronously without the need to grab
> > diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
> > index d473dcc91f54..0276447225ed 100644
> > --- a/include/drm/drm_atomic_helper.h
> > +++ b/include/drm/drm_atomic_helper.h
> > @@ -71,8 +71,8 @@ void drm_atomic_helper_commit_planes_on_crtc(struct drm_crtc_state *old_crtc_sta
> > void drm_atomic_helper_disable_planes_on_crtc(struct drm_crtc *crtc,
> > bool atomic);
> >
> > -void drm_atomic_helper_swap_state(struct drm_device *dev,
> > - struct drm_atomic_state *state);
> > +void drm_atomic_helper_swap_state(struct drm_atomic_state *state,
> > + bool stall);
> >
> > /* implementations for legacy interfaces */
> > int drm_atomic_helper_update_plane(struct drm_plane *plane,
>
>
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--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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