[igt-dev] [PATCH i-g-t] lib/igt_debugfs: Unify crc collection

[Dhinakaran Pandiyan]

On Mon, 2019-01-14 at 14:14 +0200, Mika Kahola wrote:
> For one shot crc collection, let's use the same helper function as we
> use for continuous crc collection. With this patch, we first drain
> the
> pipe from queued crc values and read the fresh crc.
> 
> Signed-off-by: Mika Kahola <mika.kahola at intel.com>
> ---
>  lib/igt_debugfs.c | 59 +++++++++++++++++++++++--------------------
> ----
>  1 file changed, 29 insertions(+), 30 deletions(-)
> 
> diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c
> index a3aca846..12e8ad78 100644
> --- a/lib/igt_debugfs.c
> +++ b/lib/igt_debugfs.c
> @@ -901,36 +901,6 @@ static void crc_sanity_checks(igt_crc_t *crc)
>  	igt_warn_on_f(all_zero, "Suspicious CRC: All values are 0.\n");
>  }
>  
> -/**
> - * igt_pipe_crc_collect_crc:
> - * @pipe_crc: pipe CRC object
> - * @out_crc: buffer for the captured CRC values
> - *
> - * Read a single CRC from @pipe_crc. This function blocks until the
> CRC is
> - * retrieved, irrespective of whether @pipe_crc has been opened with
> - * igt_pipe_crc_new() or igt_pipe_crc_new_nonblock().  @out_crc must
> be
> - * allocated by the caller.
> - *
> - * This function takes care of the pipe_crc book-keeping, it will
> start/stop
> - * the collection of the CRC.
> - *
> - * This function also calls the interactive debug with the "crc"
> domain, so you
> - * can make use of this feature to actually see the screen that is
> being CRC'd.
> - *
> - * For continuous CRC collection look at igt_pipe_crc_start(),
> - * igt_pipe_crc_get_crcs() and igt_pipe_crc_stop().
> - */
> -void igt_pipe_crc_collect_crc(igt_pipe_crc_t *pipe_crc, igt_crc_t
> *out_crc)
> -{
> -	igt_debug_wait_for_keypress("crc");
> -
> -	igt_pipe_crc_start(pipe_crc);
> -	read_one_crc(pipe_crc, out_crc);
> -	igt_pipe_crc_stop(pipe_crc);
> -
> -	crc_sanity_checks(out_crc);
> -}
> -
>  /**
>   * igt_pipe_crc_drain:
>   * @pipe_crc: pipe CRC object
> @@ -1004,6 +974,35 @@ igt_pipe_crc_get_current(int drm_fd,
> igt_pipe_crc_t *pipe_crc, igt_crc_t *crc)
>  	crc_sanity_checks(crc);
>  }
>  
> +/**
> + * igt_pipe_crc_collect_crc:
> + * @pipe_crc: pipe CRC object
> + * @out_crc: buffer for the captured CRC values
> + *
> + * Read a single CRC from @pipe_crc. This function blocks until the
> CRC is
> + * retrieved, irrespective of whether @pipe_crc has been opened with
> + * igt_pipe_crc_new() or igt_pipe_crc_new_nonblock().  @out_crc must
> be
> + * allocated by the caller.
> + *
> + * This function takes care of the pipe_crc book-keeping, it will
> start/stop
> + * the collection of the CRC.
> + *
> + * This function also calls the interactive debug with the "crc"
> domain, so you
> + * can make use of this feature to actually see the screen that is
> being CRC'd.
> + *
> + * For continuous CRC collection look at igt_pipe_crc_start(),
> + * igt_pipe_crc_get_crcs() and igt_pipe_crc_stop().
> + */
> +void igt_pipe_crc_collect_crc(igt_pipe_crc_t *pipe_crc, igt_crc_t
> *out_crc)
> +{
> +	igt_debug_wait_for_keypress("crc");
> +
> +	igt_pipe_crc_start(pipe_crc);
> +	igt_pipe_crc_drain(pipe_crc);
Since CRC collection just started in the previous line, won't this dro
the first CRC?

> +	igt_pipe_crc_get_single(pipe_crc, out_crc);
> +	igt_pipe_crc_stop(pipe_crc);
> +}
> +
>  /*
>   * Drop caches
>   */