Re: [PATCH 08/12] drm/i915: Add NV12 support to intel_framebuffer_init

Daniel Vetter
2015-05-19T08:21:35Z

On Sun, May 17, 2015 at 10:11:01PM -0700, Chandra Konduru wrote:
> This patch adds NV12 as supported format to
> intel_framebuffer_init and performs various checks.
>
> Signed-off-by: Chandra Konduru <chandra.konduru@intel.com>
> Testcase: igt/kms_nv12
> ---
> drivers/gpu/drm/i915/intel_display.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 42924a6..41cd26f 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -14043,6 +14043,33 @@ static int intel_framebuffer_init(struct drm_device *dev,
> return -EINVAL;
> }
> break;
> + case DRM_FORMAT_NV12:
> + if (INTEL_INFO(dev)->gen < 9) {
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format));
> + return -EINVAL;
> + }
> + if (!mode_cmd->offsets[1]) {
> + DRM_DEBUG("uv start offset not set\n");
> + return -EINVAL;
> + }

Nope. It's perfectly ok to have NV12 with a 0 offset for the uv plane, if
it's e.g. in a separate buffer object. Which is the part this series seems
to be completely missing - there's no code at all to look up (and store in
intel_framebuffer the 2nd i915_bo pointer) the 2nd buffer handle afaics.

You should also change your igts to use 2 separate buffers, just for test
coverage.
-Daniel

> + if (mode_cmd->pitches[0] != mode_cmd->pitches[1] ||
> + mode_cmd->handles[0] != mode_cmd->handles[1]) {
> + DRM_DEBUG("y and uv subplanes have different parameters\n");
> + return -EINVAL;
> + }
> + if (mode_cmd->modifier[1] == I915_FORMAT_MOD_Yf_TILED &&
> + (mode_cmd->offsets[1] & 0xFFF)) {
> + DRM_DEBUG("tile-Yf uv offset 0x%x isn't starting on new tile-row\n",
> + mode_cmd->offsets[1]);
> + return -EINVAL;
> + }
> + if (mode_cmd->modifier[1] == I915_FORMAT_MOD_Y_TILED &&
> + ((mode_cmd->offsets[1] % mode_cmd->pitches[1]) % 4)) {
> + DRM_DEBUG("tile-Y uv offset 0x%x isn't 4-line aligned\n",
> + mode_cmd->offsets[1]);
> + }
> + break;
> default:
> DRM_DEBUG("unsupported pixel format: %s\n",
> drm_get_format_name(mode_cmd->pixel_format));
> --
> 1.7.9.5
>
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--
Daniel Vetter
Software Engineer, Intel Corporation