[PATCH v2 1/5] drm/rockchip: vop: optimize virtual stride calculate

On 2015?07?02? 12:59, Tomasz Figa wrote:

On Fri, Jun 26, 2015 at 7:07 PM, Mark Yao [off-list ref] wrote:

quoted

vir_stride need number words of the virtual width, and fb->pitches
save bytes_per_pixel, so just div 4 switch to stride.

Signed-off-by: Mark Yao <redacted>
---
Changes in v2: None

  drivers/gpu/drm/rockchip/rockchip_drm_vop.c |    2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index 6188221..3c9f4f3 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c

@@ -644,7 +644,7 @@ static int vop_update_plane_event(struct drm_plane *plane,
         offset += (src.y1 >> 16) * fb->pitches[0];
         yrgb_mst = rk_obj->dma_addr + offset;

-       y_vir_stride = fb->pitches[0] / (fb->bits_per_pixel >> 3);
+       y_vir_stride = fb->pitches[0] >> 2;

If the unit of y_vir_stride is words then doesn't it mean that the
calculation before this patch was just invalid? If yes, shouldn't the
subject actually say "Fix virtual stride calculation"?

Best regards,
Tomasz

Hi Tomasz
     the calculation thinking before is that:
        fb->pitches[0] = surface_width * bytes_per_pixel
        surface_width = fb->pitches[0] / bytes_per_pixel
                               = fb->pitches[0] / (fb->bits_per_pixel >> 3)

    means that "y_vir_stride = surface_width",

ARGB888 one pixel is word size, So that is right for ARGB888, but wrong for other formats.

You are right, subject say "Fix virtual stride calculation" is suitable.

Best regards,
-- 
?ark Yao