On Fri, Aug 17, 2018 at 06:33:04PM +0100, Ayan Kumar Halder wrote:
> For multi-planar formats, while calculating offsets in planes with index greater than 0
> (ie second plane, third plane, etc), one needs to divide (src_x * cpp) with horizontal
> chroma subsampling factor and (src_y * pitch) with vertical chroma subsampling factor.
>
> The reason being that the planes contain subsampled (ie reduced) data (by a factor of 2) and thus the
drop the extraneous "the" at the end of the line.
> while calculating the byte position coresponding to the x and y co-ordinates, one needs to be
and drop the extraneous "be" at the end of this line.
> divide it with the sampling factor.
>
> Signed-off-by: Ayan Kumar halder <ayan.halder@xxxxxxx>
Otherwise, it looks good to me!
Reviewed-by: Liviu Dudau <liviu.dudau@xxxxxxx>
Best regards,
Liviu
> ---
> drivers/gpu/drm/drm_fb_cma_helper.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
> index b127061..47e0e2f 100644
> --- a/drivers/gpu/drm/drm_fb_cma_helper.c
> +++ b/drivers/gpu/drm/drm_fb_cma_helper.c
> @@ -86,14 +86,21 @@ dma_addr_t drm_fb_cma_get_gem_addr(struct drm_framebuffer *fb,
> {
> struct drm_gem_cma_object *obj;
> dma_addr_t paddr;
> + u8 h_div = 1, v_div = 1;
>
> obj = drm_fb_cma_get_gem_obj(fb, plane);
> if (!obj)
> return 0;
>
> paddr = obj->paddr + fb->offsets[plane];
> - paddr += fb->format->cpp[plane] * (state->src_x >> 16);
> - paddr += fb->pitches[plane] * (state->src_y >> 16);
> +
> + if (plane > 0) {
> + h_div = fb->format->hsub;
> + v_div = fb->format->vsub;
> + }
> +
> + paddr += (fb->format->cpp[plane] * (state->src_x >> 16)) / h_div;
> + paddr += (fb->pitches[plane] * (state->src_y >> 16)) / v_div;
>
> return paddr;
> }
> --
> 2.7.4
>
--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
¯\_(ツ)_/¯
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