Re: [RFC 14/21] drm/i915: Convert 'flip_queued_seqno' into 'flip_queued_request'

[Daniel Vetter <daniel@ffwll.ch>]

On Mon, Oct 06, 2014 at 03:15:18PM +0100, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>

Again on the topic of thin commit message: Some additional words about why
we can noodle around in request structures from hardirq context (those
fields are invariant after add_request) would be good. Since with the
scheduler a lot of that stuff suddenly is a lot less invariant (if we
delay the seqno allocation until we emit requests, which I'm pretty sure
we have to for a bunch of reasons).

> 
> For: VIZ-4377
> Signed-off-by: John.C.Harrison@Intel.com
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c  |    4 ++--
>  drivers/gpu/drm/i915/intel_display.c |    9 ++++++---
>  drivers/gpu/drm/i915/intel_drv.h     |    2 +-
>  3 files changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 726a8f0..52ddd19 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -547,11 +547,11 @@ static int i915_gem_pageflip_info(struct seq_file *m, void *data)
>  			if (work->flip_queued_ring) {
>  				seq_printf(m, "Flip queued on %s at seqno %u, next seqno %u [current breadcrumb %u], completed? %d\n",
>  					   work->flip_queued_ring->name,
> -					   work->flip_queued_seqno,
> +					   i915_gem_request_get_seqno(work->flip_queued_req),
>  					   dev_priv->next_seqno,
>  					   work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
>  					   i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
> -							     work->flip_queued_seqno));
> +							     i915_gem_request_get_seqno(work->flip_queued_req)));

Yeah it's no your patch, but this stuff has defintely fallen over the
edge. A prep patch to extract some helper functions to bring sanity to
i915_gem_pageflip_info's indentation levels is needed here imo.
-Daniel

>  			} else
>  				seq_printf(m, "Flip not associated with any ring\n");
>  			seq_printf(m, "Flip queued on frame %d, (was ready on frame %d), now %d\n",
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index f13bc30..26fdd96 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9879,7 +9879,7 @@ static bool __intel_pageflip_stall_check(struct drm_device *dev,
>  	if (work->flip_ready_vblank == 0) {
>  		if (work->flip_queued_ring &&
>  		    !i915_seqno_passed(work->flip_queued_ring->get_seqno(work->flip_queued_ring, true),
> -				       work->flip_queued_seqno))
> +				       i915_gem_request_get_seqno(work->flip_queued_req)))
>  			return false;
>  
>  		work->flip_ready_vblank = drm_vblank_count(dev, intel_crtc->pipe);
> @@ -10047,7 +10047,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  		if (ret)
>  			goto cleanup_unpin;
>  
> -		work->flip_queued_seqno = i915_gem_request_get_seqno(obj->last_write_req);
> +		work->flip_queued_req = obj->last_write_req;
>  		work->flip_queued_ring = obj->ring;
>  	} else {
>  		ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, ring,
> @@ -10055,10 +10055,13 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>  		if (ret)
>  			goto cleanup_unpin;
>  
> -		work->flip_queued_seqno = i915_gem_request_get_seqno(intel_ring_get_request(ring));
> +		work->flip_queued_req = intel_ring_get_request(ring);
>  		work->flip_queued_ring = ring;
>  	}
>  
> +	if (work->flip_queued_req)
> +		i915_gem_request_reference(work->flip_queued_req);
> +
>  	work->flip_queued_vblank = drm_vblank_count(dev, intel_crtc->pipe);
>  	work->enable_stall_check = true;
>  
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 418ac13..cb5af63 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -687,7 +687,7 @@ struct intel_unpin_work {
>  	u32 flip_count;
>  	u32 gtt_offset;
>  	struct intel_engine_cs *flip_queued_ring;
> -	u32 flip_queued_seqno;
> +	struct drm_i915_gem_request *flip_queued_req;
>  	int flip_queued_vblank;
>  	int flip_ready_vblank;
>  	bool enable_stall_check;
> -- 
> 1.7.9.5
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch