[Intel-gfx] [PATCH v2 1/6] drm/i915: Use atomic state to obtain load detection crtc, v2.

Ville Syrjälä ville.syrjala at linux.intel.com
Wed Feb 3 16:34:08 UTC 2016


On Wed, Feb 03, 2016 at 09:57:55AM +0100, Maarten Lankhorst wrote:
> Op 02-02-16 om 18:32 schreef Ville Syrjälä:
> > On Tue, Feb 02, 2016 at 01:48:17PM +0100, Maarten Lankhorst wrote:
> >> drm/i915: Use atomic state to obtain load detection crtc, v2.
> >>
> >> Instead of restoring dpms and a flag for whether a temp fb is allocated duplicate
> >> an atomic state before the new state is committed, and commit it the old state
> >> in intel_release_load_detect_pipe.
> >>
> >> Changes since v1:
> >> - Use a real atomic state.
> >>
> >> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> >> ---
> >> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> >> index 4d8c9f7857db..c7ba8f4a971e 100644
> >> --- a/drivers/gpu/drm/i915/intel_display.c
> >> +++ b/drivers/gpu/drm/i915/intel_display.c
> >> @@ -10361,6 +10361,7 @@ mode_fits_in_fbdev(struct drm_device *dev,
> >>  	if (obj->base.size < mode->vdisplay * fb->pitches[0])
> >>  		return NULL;
> >>  
> >> +	drm_framebuffer_reference(fb);
> >>  	return fb;
> >>  #else
> >>  	return NULL;
> >> @@ -10416,7 +10417,7 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
> >>  	struct drm_device *dev = encoder->dev;
> >>  	struct drm_framebuffer *fb;
> >>  	struct drm_mode_config *config = &dev->mode_config;
> >> -	struct drm_atomic_state *state = NULL;
> >> +	struct drm_atomic_state *state = NULL, *restore_state = NULL;
> >>  	struct drm_connector_state *connector_state;
> >>  	struct intel_crtc_state *crtc_state;
> >>  	int ret, i = -1;
> >> @@ -10425,6 +10426,8 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
> >>  		      connector->base.id, connector->name,
> >>  		      encoder->base.id, encoder->name);
> >>  
> >> +	old->restore_state = NULL;
> >> +
> >>  retry:
> >>  	ret = drm_modeset_lock(&config->connection_mutex, ctx);
> >>  	if (ret)
> >> @@ -10441,24 +10444,15 @@ retry:
> >>  	 */
> >>  
> >>  	/* See if we already have a CRTC for this connector */
> >> -	if (encoder->crtc) {
> >> -		crtc = encoder->crtc;
> >> +	if (connector->state->crtc) {
> >> +		crtc = connector->state->crtc;
> >>  
> >>  		ret = drm_modeset_lock(&crtc->mutex, ctx);
> >>  		if (ret)
> >>  			goto fail;
> >> -		ret = drm_modeset_lock(&crtc->primary->mutex, ctx);
> >> -		if (ret)
> >> -			goto fail;
> >> -
> >> -		old->dpms_mode = connector->dpms;
> >> -		old->load_detect_temp = false;
> >>  
> >>  		/* Make sure the crtc and connector are running */
> >> -		if (connector->dpms != DRM_MODE_DPMS_ON)
> >> -			connector->funcs->dpms(connector, DRM_MODE_DPMS_ON);
> >> -
> >> -		return true;
> >> +		goto found;
> >>  	}
> >>  
> >>  	/* Find an unused one (if possible) */
> >> @@ -10466,8 +10460,15 @@ retry:
> >>  		i++;
> >>  		if (!(encoder->possible_crtcs & (1 << i)))
> >>  			continue;
> >> -		if (possible_crtc->state->enable)
> >> +
> >> +		ret = drm_modeset_lock(&possible_crtc->mutex, ctx);
> >> +		if (ret)
> >> +			goto fail;
> >> +
> >> +		if (possible_crtc->state->enable) {
> >> +			drm_modeset_unlock(&possible_crtc->mutex);
> >>  			continue;
> >> +		}
> >>  
> >>  		crtc = possible_crtc;
> >>  		break;
> >> @@ -10481,23 +10482,22 @@ retry:
> >>  		goto fail;
> >>  	}
> >>  
> >> -	ret = drm_modeset_lock(&crtc->mutex, ctx);
> >> -	if (ret)
> >> -		goto fail;
> >> +found:
> >> +	intel_crtc = to_intel_crtc(crtc);
> >> +
> >>  	ret = drm_modeset_lock(&crtc->primary->mutex, ctx);
> >>  	if (ret)
> >>  		goto fail;
> >>  
> >> -	intel_crtc = to_intel_crtc(crtc);
> >> -	old->dpms_mode = connector->dpms;
> >> -	old->load_detect_temp = true;
> >> -	old->release_fb = NULL;
> >> -
> >>  	state = drm_atomic_state_alloc(dev);
> >> -	if (!state)
> >> -		return false;
> >> +	restore_state = drm_atomic_state_alloc(dev);
> >> +	if (!state || !restore_state) {
> >> +		ret = -ENOMEM;
> >> +		goto fail;
> >> +	}
> >>  
> >>  	state->acquire_ctx = ctx;
> >> +	restore_state->acquire_ctx = ctx;
> >>  
> >>  	connector_state = drm_atomic_get_connector_state(state, connector);
> >>  	if (IS_ERR(connector_state)) {
> >> @@ -10505,7 +10505,9 @@ retry:
> >>  		goto fail;
> >>  	}
> >>  
> >> -	connector_state->crtc = crtc;
> >> +	ret = drm_atomic_set_crtc_for_connector(connector_state, crtc);
> >> +	if (ret)
> >> +		goto fail;
> >>  
> >>  	crtc_state = intel_atomic_get_crtc_state(state, intel_crtc);
> >>  	if (IS_ERR(crtc_state)) {
> >> @@ -10529,7 +10531,6 @@ retry:
> >>  	if (fb == NULL) {
> >>  		DRM_DEBUG_KMS("creating tmp fb for load-detection\n");
> >>  		fb = intel_framebuffer_create_for_mode(dev, mode, 24, 32);
> >> -		old->release_fb = fb;
> >>  	} else
> >>  		DRM_DEBUG_KMS("reusing fbdev for load-detection framebuffer\n");
> >>  	if (IS_ERR(fb)) {
> >> @@ -10541,15 +10542,28 @@ retry:
> >>  	if (ret)
> >>  		goto fail;
> >>  
> >> -	drm_mode_copy(&crtc_state->base.mode, mode);
> >> +	drm_framebuffer_unreference(fb);
> >> +
> >> +	ret = drm_atomic_set_mode_for_crtc(&crtc_state->base, mode);
> >> +	if (ret)
> >> +		goto fail;
> >> +
> >> +	ret = PTR_ERR_OR_ZERO(drm_atomic_get_connector_state(restore_state, connector));
> >> +	if (!ret)
> >> +		ret = PTR_ERR_OR_ZERO(drm_atomic_get_crtc_state(restore_state, crtc));
> >> +	if (!ret)
> >> +		ret = PTR_ERR_OR_ZERO(drm_atomic_get_plane_state(restore_state, crtc->primary));
> >> +	if (ret) {
> >> +		DRM_DEBUG_KMS("Failed to create a copy of old state to restore: %i\n", ret);
> >> +		goto fail;
> >> +	}
> >>  
> >>  	if (drm_atomic_commit(state)) {
> >>  		DRM_DEBUG_KMS("failed to set mode on load-detect pipe\n");
> >> -		if (old->release_fb)
> >> -			old->release_fb->funcs->destroy(old->release_fb);
> >>  		goto fail;
> >>  	}
> >> -	crtc->primary->crtc = crtc;
> >> +
> >> +	old->restore_state = restore_state;
> >>  
> >>  	/* let the connector get through one full cycle before testing */
> >>  	intel_wait_for_vblank(dev, intel_crtc->pipe);
> >> @@ -10557,7 +10571,8 @@ retry:
> >>  
> >>  fail:
> >>  	drm_atomic_state_free(state);
> >> -	state = NULL;
> >> +	drm_atomic_state_free(restore_state);
> >> +	restore_state = state = NULL;
> >>  
> >>  	if (ret == -EDEADLK) {
> >>  		drm_modeset_backoff(ctx);
> >> @@ -10571,14 +10586,12 @@ void intel_release_load_detect_pipe(struct drm_connector *connector,
> >>  				    struct intel_load_detect_pipe *old,
> >>  				    struct drm_modeset_acquire_ctx *ctx)
> >>  {
> >> -	struct drm_device *dev = connector->dev;
> >>  	struct intel_encoder *intel_encoder =
> >>  		intel_attached_encoder(connector);
> >>  	struct drm_encoder *encoder = &intel_encoder->base;
> >> -	struct drm_crtc *crtc = encoder->crtc;
> >> +	struct drm_crtc *crtc = connector->state->crtc;
> >>  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> >> -	struct drm_atomic_state *state;
> >> -	struct drm_connector_state *connector_state;
> >> +	struct drm_atomic_state *state = old->restore_state;
> >>  	struct intel_crtc_state *crtc_state;
> >>  	int ret;
> >>  
> >> @@ -10586,50 +10599,17 @@ void intel_release_load_detect_pipe(struct drm_connector *connector,
> >>  		      connector->base.id, connector->name,
> >>  		      encoder->base.id, encoder->name);
> >>  
> >> -	if (old->load_detect_temp) {
> >> -		state = drm_atomic_state_alloc(dev);
> >> -		if (!state)
> >> -			goto fail;
> >> -
> >> -		state->acquire_ctx = ctx;
> >> -
> >> -		connector_state = drm_atomic_get_connector_state(state, connector);
> >> -		if (IS_ERR(connector_state))
> >> -			goto fail;
> >> -
> >> -		crtc_state = intel_atomic_get_crtc_state(state, intel_crtc);
> >> -		if (IS_ERR(crtc_state))
> >> -			goto fail;
> >> -
> >> -		connector_state->crtc = NULL;
> >> -
> >> -		crtc_state->base.enable = crtc_state->base.active = false;
> >> -
> >> -		ret = intel_modeset_setup_plane_state(state, crtc, NULL, NULL,
> >> -						      0, 0);
> >> -		if (ret)
> >> -			goto fail;
> >> -
> >> -		ret = drm_atomic_commit(state);
> >> -		if (ret)
> >> -			goto fail;
> >> -
> >> -		if (old->release_fb) {
> >> -			drm_framebuffer_unregister_private(old->release_fb);
> >> -			drm_framebuffer_unreference(old->release_fb);
> >> -		}
> >> -
> >> +	if (!state)
> >>  		return;
> >> -	}
> >>  
> >> -	/* Switch crtc and encoder back off if necessary */
> >> -	if (old->dpms_mode != DRM_MODE_DPMS_ON)
> >> -		connector->funcs->dpms(connector, old->dpms_mode);
> >> +	crtc_state = intel_atomic_get_crtc_state(state, intel_crtc);
> >> +	crtc_state->shared_dpll = to_intel_crtc_state(crtc->state)->shared_dpll;
> > Hmm. What's this shared_dpll stuff?
> It's for intel_modeset_clear_plls, normally we duplicate the new state and it's handled correctly,
> but when we duplicate the old state the pll may be different and unexpected behavior could occur
> otherwise.

Sounds fragile. Any chance of making it do the right thing (tm) without
having to jump through such hoops?

-- 
Ville Syrjälä
Intel OTC


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