[igt-dev] [PATCH i-g-t 1/3] lib/igt_debugfs: Add igt_crc_get_for_frame()

[Juha-Pekka Heikkila]

Series including v2 patches look ok

Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila at gmail.com>

On 21.2.2020 22.50, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Add a new helper to return the crc for a specific frame.
> Useful when we pipeline flips and crc captures more deeply
> to eliminate dead time between the flips.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>   lib/igt_debugfs.c | 31 ++++++++++++++++++++++++-------
>   lib/igt_debugfs.h |  2 ++
>   2 files changed, 26 insertions(+), 7 deletions(-)
> 
> diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c
> index 8cac9d1e148e..bf6be552057a 100644
> --- a/lib/igt_debugfs.c
> +++ b/lib/igt_debugfs.c
> @@ -945,17 +945,16 @@ void igt_pipe_crc_get_single(igt_pipe_crc_t *pipe_crc, igt_crc_t *crc)
>    * igt_pipe_crc_get_current:
>    * @drm_fd: Pointer to drm fd for vblank counter
>    * @pipe_crc: pipe CRC object
> + * @vblank: frame counter value we're looking for
>    * @crc: buffer pointer for the captured CRC value
>    *
> - * Same as igt_pipe_crc_get_single(), but will wait until a new CRC can be captured.
> - * This is useful for retrieving the current CRC in a more race free way than
> - * igt_pipe_crc_drain() + igt_pipe_crc_get_single().
> + * Same as igt_pipe_crc_get_single(), but will wait until a CRC has been captured
> + * for frame @vblank.
>    */
>   void
> -igt_pipe_crc_get_current(int drm_fd, igt_pipe_crc_t *pipe_crc, igt_crc_t *crc)
> +igt_pipe_crc_get_for_frame(int drm_fd, igt_pipe_crc_t *pipe_crc,
> +			   unsigned int vblank, igt_crc_t *crc)
>   {
> -	unsigned vblank = kmstest_get_vblank(drm_fd, pipe_crc->pipe, 0);
> -
>   	do {
>   		read_one_crc(pipe_crc, crc);
>   
> @@ -965,11 +964,29 @@ igt_pipe_crc_get_current(int drm_fd, igt_pipe_crc_t *pipe_crc, igt_crc_t *crc)
>   			igt_pipe_crc_get_single(pipe_crc, crc);
>   			return;
>   		}
> -	} while (igt_vblank_before_eq(crc->frame, vblank));
> +	} while (igt_vblank_before(crc->frame, vblank));
>   
>   	crc_sanity_checks(pipe_crc, crc);
>   }
>   
> +/**
> + * igt_pipe_crc_get_current:
> + * @drm_fd: Pointer to drm fd for vblank counter
> + * @pipe_crc: pipe CRC object
> + * @crc: buffer pointer for the captured CRC value
> + *
> + * Same as igt_pipe_crc_get_single(), but will wait until a new CRC can be captured.
> + * This is useful for retrieving the current CRC in a more race free way than
> + * igt_pipe_crc_drain() + igt_pipe_crc_get_single().
> + */
> +void
> +igt_pipe_crc_get_current(int drm_fd, igt_pipe_crc_t *pipe_crc, igt_crc_t *crc)
> +{
> +	unsigned vblank = kmstest_get_vblank(drm_fd, pipe_crc->pipe, 0) + 1;
> +
> +	return igt_pipe_crc_get_for_frame(drm_fd, pipe_crc, vblank, crc);
> +}
> +
>   /**
>    * igt_pipe_crc_collect_crc:
>    * @pipe_crc: pipe CRC object
> diff --git a/lib/igt_debugfs.h b/lib/igt_debugfs.h
> index 1e0cc108d6fb..7d1a6175ed64 100644
> --- a/lib/igt_debugfs.h
> +++ b/lib/igt_debugfs.h
> @@ -104,6 +104,8 @@ int igt_pipe_crc_get_crcs(igt_pipe_crc_t *pipe_crc, int n_crcs,
>   void igt_pipe_crc_drain(igt_pipe_crc_t *pipe_crc);
>   void igt_pipe_crc_get_single(igt_pipe_crc_t *pipe_crc, igt_crc_t *out_crc);
>   void igt_pipe_crc_get_current(int drm_fd, igt_pipe_crc_t *pipe_crc, igt_crc_t *crc);
> +void igt_pipe_crc_get_for_frame(int drm_fd, igt_pipe_crc_t *pipe_crc,
> +				unsigned int vblank, igt_crc_t *crc);
>   
>   void igt_pipe_crc_collect_crc(igt_pipe_crc_t *pipe_crc, igt_crc_t *out_crc);
>   
>