[RFC 2/2] drm/fb-helper: atomic pan_display()..

[Rob Clark]

Signed-off-by: Rob Clark <robdclark at gmail.com>
---
 drivers/gpu/drm/drm_fb_helper.c | 59 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 3549b1f..eef1687 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1192,6 +1192,59 @@ int drm_fb_helper_set_par(struct fb_info *info)
 }
 EXPORT_SYMBOL(drm_fb_helper_set_par);
 
+static int pan_display_atomic(struct fb_var_screeninfo *var,
+		struct fb_info *info)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	struct drm_device *dev = fb_helper->dev;
+	struct drm_atomic_state *state;
+	int i, ret;
+
+	state = drm_atomic_state_alloc(dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = dev->mode_config.acquire_ctx;
+retry:
+	for(i = 0; i < fb_helper->crtc_count; i++) {
+		struct drm_mode_set *mode_set;
+
+		mode_set = &fb_helper->crtc_info[i].mode_set;
+
+		mode_set->x = var->xoffset;
+		mode_set->y = var->yoffset;
+
+		ret = drm_atomic_helper_set_config_impl(mode_set, state);
+		if (ret != 0)
+			goto fail;
+	}
+
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	// XXX if fail, revert modeset[i]->x,y?? legacy path doesn't seem to do it either..
+
+	info->var.xoffset = var->xoffset;
+	info->var.yoffset = var->yoffset;
+
+	return 0;
+
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	goto retry;
+}
+
 /**
  * drm_fb_helper_pan_display - implementation for ->fb_pan_display
  * @var: updated screen information
@@ -1215,6 +1268,11 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
 		return -EBUSY;
 	}
 
+	if (drm_core_check_feature(dev, DRIVER_ATOMIC)) {
+		ret = pan_display_atomic(var, info);
+		goto unlock;
+	}
+
 	for (i = 0; i < fb_helper->crtc_count; i++) {
 		modeset = &fb_helper->crtc_info[i].mode_set;
 
@@ -1229,6 +1287,7 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
 			}
 		}
 	}
+unlock:
 	drm_modeset_unlock_all(dev);
 	return ret;
 }
-- 
2.4.3