Commit ded74caf authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/fb-helper: Clip damage area horizontally 



Clip the damage area horizontally if only a single scanline has been
changed. This is helpful to reduce the memcpy overhead for small writes.

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-6-tzimmermann@suse.de
parent fe23b56f

drivers/gpu/drm/drm_fb_helper.c

+12 −0
Original line number Diff line number Diff line
@@ -690,6 +690,18 @@ static void drm_fb_helper_memory_range_to_clip(struct fb_info *info, off_t off, 
	u32 x2 = info->var.xres;

	u32 y2 = DIV_ROUND_UP(end, info->fix.line_length);



	if ((y2 - y1) == 1) {

		/*

		 * We've only written to a single scanline. Try to reduce

		 * the number of horizontal pixels that need an update.

		 */

		off_t bit_off = (off % info->fix.line_length) * 8;

		off_t bit_end = (end % info->fix.line_length) * 8;



		x1 = bit_off / info->var.bits_per_pixel;

		x2 = DIV_ROUND_UP(bit_end, info->var.bits_per_pixel);

	}



	drm_rect_init(clip, x1, y1, x2 - x1, y2 - y1);

}