Hi,

I tested your patch with kms_cursor_crc, and everything worked as expected! Really nice patch :)

I just have some tiny comments inline.

On 01/24, Mamta Shukla wrote:

Use the alpha value to blend vaddr_src with vaddr_dst instead of overwriting it in blend().

Signed-off-by: Mamta Shukla mamtashukla555@gmail.com

drivers/gpu/drm/vkms/vkms_crc.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_crc.c b/drivers/gpu/drm/vkms/vkms_crc.c index 9d9e8146db90..13d5ffed9135 100644 --- a/drivers/gpu/drm/vkms/vkms_crc.c +++ b/drivers/gpu/drm/vkms/vkms_crc.c @@ -70,7 +70,8 @@ static void blend(void *vaddr_dst, void *vaddr_src,

int y_limit = y_src + h_dst; int x_limit = x_src + w_dst;

• u8 alpha, r_src, r_dst, g_src, g_dst, b_src, b_dst;
• u8 r_alpha, g_alpha, b_alpha; for (i = y_src, i_dst = y_dst; i < y_limit; ++i) { for (j = x_src, j_dst = x_dst; j < x_limit; ++j) { offset_dst = crc_dst->offset

@@ -80,8 +81,23 @@ static void blend(void *vaddr_dst, void *vaddr_src, + (i * crc_src->pitch) + (j * crc_src->cpp);

• 	memcpy(vaddr_dst + offset_dst,
  

• 	       vaddr_src + offset_src, sizeof(u32));
  

• 	/*Currently handles alpha values for fully opaque or fully transparent */
  

• 	alpha = (u8)((*(u32 *)(vaddr_src + offset_src)) >> 24);
  

• 	alpha = alpha/255;
  

Add spaces between '/'.

• 	r_src = (u8)((*(u32 *)(vaddr_src + offset_src)) >> 16 & 0xff);
  

• 	g_src = (u8)((*(u32 *)(vaddr_src + offset_src)) >> 8  & 0xff);
  

• 	b_src = (u8)((*(u32 *)(vaddr_src + offset_src)) & 0xff);
  

• 	r_dst = (u8)((*(u32 *)(vaddr_dst + offset_dst)) >> 16 & 0xff);
  

• 	g_dst = (u8)((*(u32 *)(vaddr_dst + offset_dst)) >> 8 & 0xff);
  

• 	b_dst = (u8)((*(u32 *)(vaddr_dst + offset_dst)) & 0xff);
  

Since these operations are very similar, it could be better to create one inline function or macro to reduce the code duplication. I'm not sure, but I suspect that Linux already provides some macros for this sort of operations (again, I'm not sure).

• 	/*Pre-multiplied alpha for blending */
  

• 	r_alpha = (r_src) + (r_dst * (1 -alpha));
  

• 	g_alpha = (g_src) + (g_dst * (1 -alpha));
  

• 	b_alpha = (b_src) + (b_dst * (1 -alpha));
  

Add space between '-'.

• 	memset(vaddr_dst + offset_dst, b_alpha, sizeof(u8));
  

• 	memset(vaddr_dst + offset_dst + 1, g_alpha, sizeof(u8));			
  

Take care with extra spaces at the end.

Finally, remember to run checkpatch in your patches.

• 	memset(vaddr_dst + offset_dst + 2, r_alpha, sizeof(u8));
  

  } i_dst++; }

-- 2.17.1