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Commit 9b613022 authored by Matt Roper's avatar Matt Roper
Browse files

drm/i915/gen9: Re-allocate DDB only for changed pipes 



When a display update triggers a DDB re-allocation, we should start by
assuming that only the updated pipes need to be re-allocated (we have
logic later that may add additional pipes if, e.g., a modeset triggers a
change to the global allocation).

We were erroneously using the _active_ pipes as our starting point
rather than the changed pipes.  This causes us to grab CRTC locks that
we didn't actually need, reducing parallelism.  Given the recent
non-blocking atomic changes, it also causes legacy pageflips against one
CRTC to return -EBUSY if there's an outstanding pageflip against a
different CRTC (a situation easily triggered via compositors like
Weston).

Fixes: 98d39494 ("drm/i915/gen9: Compute DDB allocation at atomic check time (v4)")
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: default avatarMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467070964-14864-1-git-send-email-matthew.d.roper@intel.com


Reviewed-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
parent bdaa2dfb

drivers/gpu/drm/i915/intel_pm.c

+14 −1
Original line number Diff line number Diff line
@@ -3879,6 +3879,19 @@ static int skl_update_pipe_wm(struct drm_crtc_state *cstate, 
	return 0;

}



static uint32_t

pipes_modified(struct drm_atomic_state *state)

{

	struct drm_crtc *crtc;

	struct drm_crtc_state *cstate;

	uint32_t i, ret = 0;



	for_each_crtc_in_state(state, crtc, cstate, i)

		ret |= drm_crtc_mask(crtc);



	return ret;

}



static int

skl_compute_ddb(struct drm_atomic_state *state)

{
@@ -3887,7 +3900,7 @@ skl_compute_ddb(struct drm_atomic_state *state) 
	struct intel_atomic_state *intel_state = to_intel_atomic_state(state);

	struct intel_crtc *intel_crtc;

	struct skl_ddb_allocation *ddb = &intel_state->wm_results.ddb;

	unsigned realloc_pipes = dev_priv->active_crtcs;

	uint32_t realloc_pipes = pipes_modified(state);

	int ret;



	/*