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@xxxxxxx> Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> --- 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