[PATCH v2 4/6] drm/fb-helper: Perform damage handling in deferred-I/O helper

[Thomas Zimmermann]

Call fb_dirty directly from drm_fb_helper_deferred_io() to avoid the
latency of running the damage worker.

The deferred-I/O helper drm_fb_helper_deferred_io() runs in a worker
thread at regular intervals as part of writing to mmaped framebuffer
memory. It used to schedule the fbdev damage worker to flush the
framebuffer. Changing this to flushing the framebuffer directly avoids
the latency introduced by the damage worker.

v2:
	* remove fb_dirty from defio in separate patch (Daniel)

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/drm_fb_helper.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index b3a731b9170a6..cdbf03e941b2b 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -666,10 +666,16 @@ void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagerefli
 
 	if (min_off < max_off) {
 		drm_fb_helper_memory_range_to_clip(info, min_off, max_off - min_off, &damage_area);
-		drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
-				     drm_rect_width(&damage_area),
-				     drm_rect_height(&damage_area));
+		drm_fb_helper_add_damage_clip(helper, damage_area.x1, damage_area.y1,
+					      drm_rect_width(&damage_area),
+					      drm_rect_height(&damage_area));
 	}
+
+	/*
+	 * Flushes all dirty pages from mmap's pageref list and the
+	 * areas that have been written by struct fb_ops callbacks.
+	 */
+	drm_fb_helper_fb_dirty(helper);
 }
 EXPORT_SYMBOL(drm_fb_helper_deferred_io);
 
-- 
2.38.1