Write helpers used to mark the complete screen as dirty. This is wasteful for writes that only change a small portion of the screen. Fix the problem by computing the damaged area from the written memory range and perform damage handling accordingly.
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de Reviewed-by: Javier Martinez Canillas javierm@redhat.com --- drivers/gpu/drm/drm_fb_helper.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 3d6d0b1464e7..4d5410dd96c5 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -754,11 +754,18 @@ EXPORT_SYMBOL(drm_fb_helper_sys_read); ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf, size_t count, loff_t *ppos) { + loff_t pos = *ppos; ssize_t ret; + struct drm_rect damage_area;
ret = fb_sys_write(info, buf, count, ppos); - if (ret > 0) - drm_fb_helper_damage(info, 0, 0, info->var.xres, info->var.yres); + if (ret <= 0) + return ret; + + drm_fb_helper_memory_range_to_clip(info, pos, ret, &damage_area); + drm_fb_helper_damage(info, damage_area.x1, damage_area.y1, + drm_rect_width(&damage_area), + drm_rect_height(&damage_area));
return ret; } @@ -2237,6 +2244,7 @@ static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf, loff_t pos = *ppos; size_t total_size; ssize_t ret; + struct drm_rect damage_area; int err = 0;
if (info->screen_size) @@ -2265,13 +2273,19 @@ static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf, else ret = fb_write_screen_buffer(info, buf, count, pos);
- if (ret > 0) - *ppos += ret; + if (ret < 0) + return ret; /* return last error, if any */ + else if (!ret) + return err; /* return previous error, if any */
- if (ret > 0) - drm_fb_helper_damage(info, 0, 0, info->var.xres_virtual, info->var.yres_virtual); + *ppos += ret;
- return ret ? ret : err; + drm_fb_helper_memory_range_to_clip(info, pos, ret, &damage_area); + drm_fb_helper_damage(info, damage_area.x1, damage_area.y1, + drm_rect_width(&damage_area), + drm_rect_height(&damage_area)); + + return ret; }
static void drm_fbdev_fb_fillrect(struct fb_info *info,