[Intel-gfx] [PATCH 4/6] drm/i915: Added support to allow change in FB pitch across flips

Daniel Vetter daniel at ffwll.ch
Thu Aug 14 16:27:40 CEST 2014


On Thu, Aug 14, 2014 at 02:54:25PM +0530, akash.goel at intel.com wrote:
> From: Akash Goel <akash.goel at intel.com>
> 
> This patch removes the check for change in pitch of frame buffer
> across page flips. Since there is a support for MMIO based page
> flips, we can update the plane registers to update the
> FB pitch & accordingly the offsets in LINOFF/TILEOFF registers.
> The plane registers are updated atomically, using the mechanism
> used for Sprite planes update. Doing so also requires deferring of
> MMIO flip, if issued in interrupt context.
> 
> Signed-off-by: Akash Goel <akash.goel at intel.com>
> Signed-off-by: Pallavi G<pallavi.g at intel.com>

This looks like a separate patch from the overall work in this series. It
definitely needs an i-g-t testcase, preferrably one to check that the
update is indeed atomic.
-Daniel

> ---
>  drivers/gpu/drm/i915/intel_display.c | 51 +++++++++++++++++++++++++++++++++---
>  drivers/gpu/drm/i915/intel_drv.h     |  5 ++++
>  drivers/gpu/drm/i915/intel_sprite.c  |  4 +--
>  3 files changed, 54 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 47a5424..a75d1a0 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9542,6 +9542,29 @@ static bool use_mmio_flip(struct intel_engine_cs *ring,
>  		return ring != obj->ring;
>  }
>  
> +static void intel_mmio_flip_work_fn(struct work_struct *work)
> +{
> +	struct intel_mmio_flip *mmio_flip =
> +		container_of(work, struct intel_mmio_flip, work);
> +	struct intel_crtc *intel_crtc =
> +		container_of(mmio_flip, struct intel_crtc, mmio_flip);
> +	struct drm_device *dev = intel_crtc->base.dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct drm_crtc *crtc = &intel_crtc->base;
> +	u32 start_vbl_count;
> +	bool atomic_update;
> +
> +	atomic_update = intel_pipe_update_start(intel_crtc, &start_vbl_count);
> +
> +	intel_mark_page_flip_active(intel_crtc);
> +
> +	dev_priv->display.update_primary_plane(crtc, crtc->primary->fb,
> +							crtc->x, crtc->y);
> +
> +	if (atomic_update)
> +		intel_pipe_update_end(intel_crtc, start_vbl_count);
> +}
> +
>  static void intel_do_mmio_flip(struct intel_crtc *intel_crtc)
>  {
>  	struct drm_device *dev = intel_crtc->base.dev;
> @@ -9552,6 +9575,17 @@ static void intel_do_mmio_flip(struct intel_crtc *intel_crtc)
>  	u32 dspcntr;
>  	u32 reg;
>  
> +	/* if we are in interrupt context and there is a need to update
> +	   all the plane registers (atomically), then defer the flip to
> +	   a process context, as we can then wait for the next vblank boundary */
> +	if (intel_crtc->unpin_work->update_all_plane_reg) {
> +		if (in_atomic())
> +			schedule_work(&intel_crtc->mmio_flip.work);
> +		else
> +			intel_mmio_flip_work_fn(&intel_crtc->mmio_flip.work);
> +		return;
> +	}
> +
>  	intel_mark_page_flip_active(intel_crtc);
>  
>  	reg = DSPCNTR(intel_crtc->plane);
> @@ -9685,6 +9719,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  	struct intel_unpin_work *work;
>  	struct intel_engine_cs *ring;
>  	unsigned long flags;
> +	bool update_all_plane_reg = 0;
>  	int ret;
>  
>  	/*
> @@ -9706,7 +9741,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  	if (INTEL_INFO(dev)->gen > 3 &&
>  	    (fb->offsets[0] != crtc->primary->fb->offsets[0] ||
>  	     fb->pitches[0] != crtc->primary->fb->pitches[0]))
> -		return -EINVAL;
> +		update_all_plane_reg = 1;
>  
>  	if (i915_terminally_wedged(&dev_priv->gpu_error))
>  		goto out_hang;
> @@ -9718,6 +9753,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  	work->event = event;
>  	work->crtc = crtc;
>  	work->old_fb_obj = intel_fb_obj(old_fb);
> +	work->update_all_plane_reg = update_all_plane_reg;
>  	INIT_WORK(&work->work, intel_unpin_work_fn);
>  
>  	ret = drm_crtc_vblank_get(crtc);
> @@ -9785,9 +9821,14 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  	if (use_mmio_flip(ring, obj))
>  		ret = intel_queue_mmio_flip(dev, crtc, fb, obj, ring,
>  					    page_flip_flags);
> -	else
> -		ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, ring,
> -				page_flip_flags);
> +	else {
> +		if (update_all_plane_reg)
> +			ret = -EINVAL;
> +		else
> +			ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, ring,
> +					page_flip_flags);
> +	}
> +
>  	if (ret)
>  		goto cleanup_unpin;
>  
> @@ -11912,6 +11953,8 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
>  	intel_crtc->cursor_cntl = ~0;
>  	intel_crtc->cursor_size = ~0;
>  
> +	INIT_WORK(&intel_crtc->mmio_flip.work, intel_mmio_flip_work_fn);
> +
>  	BUG_ON(pipe >= ARRAY_SIZE(dev_priv->plane_to_crtc_mapping) ||
>  	       dev_priv->plane_to_crtc_mapping[intel_crtc->plane] != NULL);
>  	dev_priv->plane_to_crtc_mapping[intel_crtc->plane] = &intel_crtc->base;
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index a30abd9..0cb685a 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -375,6 +375,7 @@ struct intel_pipe_wm {
>  struct intel_mmio_flip {
>  	u32 seqno;
>  	u32 ring_id;
> +	struct work_struct work;
>  };
>  
>  struct intel_crtc {
> @@ -659,6 +660,7 @@ struct intel_unpin_work {
>  	u32 flip_count;
>  	u32 gtt_offset;
>  	bool enable_stall_check;
> +	bool update_all_plane_reg;
>  };
>  
>  struct intel_set_config {
> @@ -848,6 +850,9 @@ void intel_prepare_page_flip(struct drm_device *dev, int plane);
>  void intel_finish_page_flip(struct drm_device *dev, int pipe);
>  void intel_finish_page_flip_plane(struct drm_device *dev, int plane);
>  
> +bool intel_pipe_update_start(struct intel_crtc *crtc, uint32_t *start_vbl_count);
> +void intel_pipe_update_end(struct intel_crtc *crtc, u32 start_vbl_count);
> +
>  /* shared dpll functions */
>  struct intel_shared_dpll *intel_crtc_to_shared_dpll(struct intel_crtc *crtc);
>  void assert_shared_dpll(struct drm_i915_private *dev_priv,
> diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
> index 0bdb00b..5e4a641 100644
> --- a/drivers/gpu/drm/i915/intel_sprite.c
> +++ b/drivers/gpu/drm/i915/intel_sprite.c
> @@ -46,7 +46,7 @@ static int usecs_to_scanlines(const struct drm_display_mode *mode, int usecs)
>  	return DIV_ROUND_UP(usecs * mode->crtc_clock, 1000 * mode->crtc_htotal);
>  }
>  
> -static bool intel_pipe_update_start(struct intel_crtc *crtc, uint32_t *start_vbl_count)
> +bool intel_pipe_update_start(struct intel_crtc *crtc, uint32_t *start_vbl_count)
>  {
>  	struct drm_device *dev = crtc->base.dev;
>  	const struct drm_display_mode *mode = &crtc->config.adjusted_mode;
> @@ -112,7 +112,7 @@ static bool intel_pipe_update_start(struct intel_crtc *crtc, uint32_t *start_vbl
>  	return true;
>  }
>  
> -static void intel_pipe_update_end(struct intel_crtc *crtc, u32 start_vbl_count)
> +void intel_pipe_update_end(struct intel_crtc *crtc, u32 start_vbl_count)
>  {
>  	struct drm_device *dev = crtc->base.dev;
>  	enum pipe pipe = crtc->pipe;
> -- 
> 1.9.2
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch



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