Re: [igt-dev] [PATCH i-g-t v2 04/13] igt: fb: Move i915 YUV buffer clearing code to a function

Ville Syrjälä
2019-01-10T14:38:59Z

On Thu, Jan 10, 2019 at 11:10:09AM +0100, Paul Kocialkowski wrote:
> On Tue, 2019-01-08 at 16:19 +0100, Maxime Ripard wrote:
> > The YUV buffer allocation path for the i915 driver also has some code to
> > clear a YUV buffer.
> >
> > As that is going to be useful for all the other drivers, let's move it to
> > a separate function.
> >
> > Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
>
> I'm not really sure why clearing the buffers is a useful thing to do
> and why we should only do it for YUV and not RGB formats.

0 = black for RGB, 0 != black for YUV. The memset was just to make
things more consistent. But not sure if any test would actually
fail if we just drop the memset.

>
> Anyway, since this code was already there and the refactoring
> definitely makes sense:
>
> Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
>
> Cheers,
>
> Paul
>
> > ---
> > lib/igt_fb.c | 80 +++++++++++++++++++++++++++-------------------------
> > 1 file changed, 42 insertions(+), 38 deletions(-)
> >
> > diff --git a/lib/igt_fb.c b/lib/igt_fb.c
> > index 45691fd441d9..d69c3fb2d38d 100644
> > --- a/lib/igt_fb.c
> > +++ b/lib/igt_fb.c
> > @@ -484,6 +484,47 @@ uint64_t igt_fb_tiling_to_mod(uint64_t tiling)
> > }
> > }
> >
> > +static void clear_yuv_buffer(struct igt_fb *fb)
> > +{
> > + bool full_range = fb->color_range == IGT_COLOR_YCBCR_FULL_RANGE;
> > + void *ptr;
> > +
> > + igt_assert(igt_format_is_yuv(fb->drm_format));
> > +
> > + /* Ensure the framebuffer is preallocated */
> > + ptr = igt_fb_map_buffer(fb->fd, fb);
> > + igt_assert(*(uint32_t *)ptr == 0);
> > +
> > + switch (fb->drm_format) {
> > + case DRM_FORMAT_NV12:
> > + memset(ptr + fb->offsets[0],
> > + full_range ? 0x00 : 0x10,
> > + fb->strides[0] * fb->plane_height[0]);
> > + memset(ptr + fb->offsets[1],
> > + 0x80,
> > + fb->strides[1] * fb->plane_height[1]);
> > + break;
> > + case DRM_FORMAT_XYUV8888:
> > + wmemset(ptr + fb->offsets[0], full_range ? 0x00008080 : 0x00108080,
> > + fb->strides[0] * fb->plane_height[0] / sizeof(wchar_t));
> > + break;
> > + case DRM_FORMAT_YUYV:
> > + case DRM_FORMAT_YVYU:
> > + wmemset(ptr + fb->offsets[0],
> > + full_range ? 0x80008000 : 0x80108010,
> > + fb->strides[0] * fb->plane_height[0] / sizeof(wchar_t));
> > + break;
> > + case DRM_FORMAT_UYVY:
> > + case DRM_FORMAT_VYUY:
> > + wmemset(ptr + fb->offsets[0],
> > + full_range ? 0x00800080 : 0x10801080,
> > + fb->strides[0] * fb->plane_height[0] / sizeof(wchar_t));
> > + break;
> > + }
> > +
> > + igt_fb_unmap_buffer(fb, ptr);
> > +}
> > +
> > /* helpers to create nice-looking framebuffers */
> > static int create_bo_for_fb(struct igt_fb *fb)
> > {
> > @@ -501,50 +542,13 @@ static int create_bo_for_fb(struct igt_fb *fb)
> > fb->is_dumb = false;
> >
> > if (is_i915_device(fd)) {
> > - void *ptr;
> > - bool full_range = fb->color_range == IGT_COLOR_YCBCR_FULL_RANGE;
> >
> > fb->gem_handle = gem_create(fd, fb->size);
> >
> > gem_set_tiling(fd, fb->gem_handle,
> > igt_fb_mod_to_tiling(fb->tiling),
> > fb->strides[0]);
> > -
> > - gem_set_domain(fd, fb->gem_handle,
> > - I915_GEM_DOMAIN_GTT, I915_GEM_DOMAIN_GTT);
> > -
> > - /* Ensure the framebuffer is preallocated */
> > - ptr = gem_mmap__gtt(fd, fb->gem_handle,
> > - fb->size, PROT_READ | PROT_WRITE);
> > - igt_assert(*(uint32_t *)ptr == 0);
> > -
> > - switch (fb->drm_format) {
> > - case DRM_FORMAT_NV12:
> > - memset(ptr + fb->offsets[0],
> > - full_range ? 0x00 : 0x10,
> > - fb->strides[0] * fb->plane_height[0]);
> > - memset(ptr + fb->offsets[1],
> > - 0x80,
> > - fb->strides[1] * fb->plane_height[1]);
> > - break;
> > - case DRM_FORMAT_XYUV8888:
> > - wmemset(ptr + fb->offsets[0], full_range ? 0x00008080 : 0x00108080,
> > - fb->strides[0] * fb->plane_height[0] / sizeof(wchar_t));
> > - break;
> > - case DRM_FORMAT_YUYV:
> > - case DRM_FORMAT_YVYU:
> > - wmemset(ptr + fb->offsets[0],
> > - full_range ? 0x80008000 : 0x80108010,
> > - fb->strides[0] * fb->plane_height[0] / sizeof(wchar_t));
> > - break;
> > - case DRM_FORMAT_UYVY:
> > - case DRM_FORMAT_VYUY:
> > - wmemset(ptr + fb->offsets[0],
> > - full_range ? 0x00800080 : 0x10801080,
> > - fb->strides[0] * fb->plane_height[0] / sizeof(wchar_t));
> > - break;
> > - }
> > - gem_munmap(ptr, fb->size);
> > + clear_yuv_buffer(fd);
> >
> > return fb->gem_handle;
> > } else {
> --
> Paul Kocialkowski, Bootlin
> Embedded Linux and kernel engineering
> https://bootlin.com

--
Ville Syrjälä
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