[Intel-gfx] [PATCH v3 1/5] drm/i915: Add enable/disable flip done and flip done handler
Paulo Zanoni
paulo.r.zanoni at intel.com
Wed Jun 10 22:33:06 UTC 2020
Em qui, 2020-05-28 às 11:09 +0530, Karthik B S escreveu:
> Add enable/disable flip done functions and the flip done handler
> function which handles the flip done interrupt.
>
> Enable the flip done interrupt in IER.
>
> Enable flip done function is called before writing the
> surface address register as the write to this register triggers
> the flip done interrupt
>
> Flip done handler is used to send the page flip event as soon as the
> surface address is written as per the requirement of async flips.
> The interrupt is disabled after the event is sent.
>
> v2: -Change function name from icl_* to skl_* (Paulo)
> -Move flip handler to this patch (Paulo)
> -Remove vblank_put() (Paulo)
> -Enable flip done interrupt for gen9+ only (Paulo)
> -Enable flip done interrupt in power_well_post_enable hook (Paulo)
> -Removed the event check in flip done handler to handle async
> flips without pageflip events.
>
> v3: -Move skl_disable_flip_done out of interrupt handler (Paulo)
> -Make the pending vblank event NULL in the begining of
> flip_done_handler to remove sporadic WARN_ON that is seen.
>
> Signed-off-by: Karthik B S <karthik.b.s at intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 10 ++++
> drivers/gpu/drm/i915/i915_irq.c | 52 ++++++++++++++++++++
> drivers/gpu/drm/i915/i915_irq.h | 2 +
> 3 files changed, 64 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index f40b909952cc..48cc1fc9bc5a 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -15530,6 +15530,13 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
>
> intel_dbuf_pre_plane_update(state);
>
> + for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
> + if (new_crtc_state->uapi.async_flip) {
> + skl_enable_flip_done(&crtc->base);
> + break;
> + }
> + }
> +
> /* Now enable the clocks, plane, pipe, and connectors that we set up. */
> dev_priv->display.commit_modeset_enables(state);
>
> @@ -15551,6 +15558,9 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
> drm_atomic_helper_wait_for_flip_done(dev, &state->base);
>
> for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
> + if (new_crtc_state->uapi.async_flip)
> + skl_disable_flip_done(&crtc->base);
> +
> if (new_crtc_state->hw.active &&
> !needs_modeset(new_crtc_state) &&
> !new_crtc_state->preload_luts &&
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index efdd4c7b8e92..632e7b1deb87 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -1295,6 +1295,23 @@ display_pipe_crc_irq_handler(struct drm_i915_private *dev_priv,
> u32 crc4) {}
> #endif
>
> +static void flip_done_handler(struct drm_i915_private *dev_priv,
> + unsigned int pipe)
> +{
> + struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
> + struct drm_crtc_state *crtc_state = crtc->base.state;
> + struct drm_pending_vblank_event *e = crtc_state->event;
> + struct drm_device *dev = &dev_priv->drm;
> + unsigned long irqflags;
> +
> + crtc_state->event = NULL;
> +
> + spin_lock_irqsave(&dev->event_lock, irqflags);
> +
> + drm_crtc_send_vblank_event(&crtc->base, e);
I don't think this is what we want. With this, the events the Kernel
sends us all have the same sequence and timestamp. In fact, the IGT
test you submitted fails because of this.
In my original hackish proof-of-concept patch I had changed
drm_update_vblank_count() to force diff=1 in order to always send
events and I also changed g4x_get_vblank_counter() to get the counter
from FLIPCOUNT (which updates every time there's a flip) instead of
FRMCOUNT (which doesn't seem to increment when you do async flips).
That is a drastic change, but the patch was just a PoC so I didn't care
about keeping anything else working.
One thing that confused me a little bit when dealing the the
vblank/flip event interface from drm.ko is that "flips" and "vblanks"
seem to be changed interchangeably, which is confusing for async flips:
if you keep forever doing async flips in the very first few scanlines
you never actually reach the "vblank" period, yet you keep flipping
your frame. Then, what should your expectation regarding events be?
I think we may need to check how the other drivers handle async vblanks
(or how drm.ko wants us to handle async vblanks). Should we increment
sequence on every async flip? What about the timestamp?
Daniel, Ville, do you happen to know the proper semantics here?
There's certainly some adjustment to do to both this patch and the IGT.
> +
> + spin_unlock_irqrestore(&dev->event_lock, irqflags);
> +}
>
> static void hsw_pipe_crc_irq_handler(struct drm_i915_private *dev_priv,
> enum pipe pipe)
> @@ -2388,6 +2405,9 @@ gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
> if (iir & GEN8_PIPE_VBLANK)
> intel_handle_vblank(dev_priv, pipe);
>
> + if (iir & GEN9_PIPE_PLANE1_FLIP_DONE)
> + flip_done_handler(dev_priv, pipe);
> +
> if (iir & GEN8_PIPE_CDCLK_CRC_DONE)
> hsw_pipe_crc_irq_handler(dev_priv, pipe);
>
> @@ -2669,6 +2689,19 @@ int bdw_enable_vblank(struct drm_crtc *crtc)
> return 0;
> }
>
> +void skl_enable_flip_done(struct drm_crtc *crtc)
> +{
> + struct drm_i915_private *dev_priv = to_i915(crtc->dev);
> + enum pipe pipe = to_intel_crtc(crtc)->pipe;
> + unsigned long irqflags;
> +
> + spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
> +
> + bdw_enable_pipe_irq(dev_priv, pipe, GEN9_PIPE_PLANE1_FLIP_DONE);
> +
> + spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
> +}
> +
> /* Called from drm generic code, passed 'crtc' which
> * we use as a pipe index
> */
> @@ -2729,6 +2762,19 @@ void bdw_disable_vblank(struct drm_crtc *crtc)
> spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
> }
>
> +void skl_disable_flip_done(struct drm_crtc *crtc)
> +{
> + struct drm_i915_private *dev_priv = to_i915(crtc->dev);
> + enum pipe pipe = to_intel_crtc(crtc)->pipe;
> + unsigned long irqflags;
> +
> + spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
> +
> + bdw_disable_pipe_irq(dev_priv, pipe, GEN9_PIPE_PLANE1_FLIP_DONE);
> +
> + spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
> +}
> +
> static void ibx_irq_reset(struct drm_i915_private *dev_priv)
> {
> struct intel_uncore *uncore = &dev_priv->uncore;
> @@ -2936,6 +2982,9 @@ void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv,
> u32 extra_ier = GEN8_PIPE_VBLANK | GEN8_PIPE_FIFO_UNDERRUN;
> enum pipe pipe;
>
> + if (INTEL_GEN(dev_priv) >= 9)
> + extra_ier |= GEN9_PIPE_PLANE1_FLIP_DONE;
> +
> spin_lock_irq(&dev_priv->irq_lock);
>
> if (!intel_irqs_enabled(dev_priv)) {
> @@ -3410,6 +3459,9 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
> de_pipe_enables = de_pipe_masked | GEN8_PIPE_VBLANK |
> GEN8_PIPE_FIFO_UNDERRUN;
>
> + if (INTEL_GEN(dev_priv) >= 9)
> + de_pipe_enables |= GEN9_PIPE_PLANE1_FLIP_DONE;
> +
> de_port_enables = de_port_masked;
> if (IS_GEN9_LP(dev_priv))
> de_port_enables |= BXT_DE_PORT_HOTPLUG_MASK;
> diff --git a/drivers/gpu/drm/i915/i915_irq.h b/drivers/gpu/drm/i915/i915_irq.h
> index 25f25cd95818..2f10c8135116 100644
> --- a/drivers/gpu/drm/i915/i915_irq.h
> +++ b/drivers/gpu/drm/i915/i915_irq.h
> @@ -112,11 +112,13 @@ int i915gm_enable_vblank(struct drm_crtc *crtc);
> int i965_enable_vblank(struct drm_crtc *crtc);
> int ilk_enable_vblank(struct drm_crtc *crtc);
> int bdw_enable_vblank(struct drm_crtc *crtc);
> +void skl_enable_flip_done(struct drm_crtc *crtc);
> void i8xx_disable_vblank(struct drm_crtc *crtc);
> void i915gm_disable_vblank(struct drm_crtc *crtc);
> void i965_disable_vblank(struct drm_crtc *crtc);
> void ilk_disable_vblank(struct drm_crtc *crtc);
> void bdw_disable_vblank(struct drm_crtc *crtc);
> +void skl_disable_flip_done(struct drm_crtc *crtc);
>
> void gen2_irq_reset(struct intel_uncore *uncore);
> void gen3_irq_reset(struct intel_uncore *uncore, i915_reg_t imr,
More information about the Intel-gfx
mailing list