[igt-dev] [PATCH i-g-t v2] lib/debugfs: Sanity check even discarded CRCs

[Souza, Jose]

On Fri, 2020-05-15 at 17:38 +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> We currently only spot check some of the CRCs. We should check them
> all. This will probably cause failures on machines with PSR as
> it looks like the CRC captured after PSR exit is bogus. Or at least
> it is on ICL. We should probably just disable PSR whenever CRC
> capturing is active.

There was some PSR changes around CRC, it should not be a problem anymore.

> 
> v2: Rebase
> 

Reviewed-by: José Roberto de Souza <jose.souza at intel.com>

> Cc: José Roberto de Souza <jose.souza at intel.com>
> Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com> #v1
> References: https://bugs.freedesktop.org/show_bug.cgi?id=106974
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  lib/igt_debugfs.c | 47 ++++++++++++++++++++++-------------------------
>  1 file changed, 22 insertions(+), 25 deletions(-)
> 
> diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c
> index 0506707852f0..73975f922e19 100644
> --- a/lib/igt_debugfs.c
> +++ b/lib/igt_debugfs.c
> @@ -759,6 +759,26 @@ static bool pipe_crc_init_from_string(igt_pipe_crc_t *pipe_crc, igt_crc_t *crc,
>  	return true;
>  }
>  
> +static void crc_sanity_checks(igt_pipe_crc_t *pipe_crc, igt_crc_t *crc)
> +{
> +	bool all_zero = true;
> +
> +	/* Any CRC value can be considered valid on amdgpu hardware. */
> +	if (is_amdgpu_device(pipe_crc->fd))
> +		return;
> +
> +	for (int i = 0; i < crc->n_words; i++) {
> +		igt_warn_on_f(crc->crc[i] == 0xffffffff,
> +			      "Suspicious CRC: it looks like the CRC "
> +			      "read back was from a register in a powered "
> +			      "down well\n");
> +		if (crc->crc[i])
> +			all_zero = false;
> +	}
> +
> +	igt_warn_on_f(all_zero, "Suspicious CRC: All values are 0.\n");
> +}
> +
>  static int read_crc(igt_pipe_crc_t *pipe_crc, igt_crc_t *out)
>  {
>  	ssize_t bytes_read;
> @@ -776,6 +796,8 @@ static int read_crc(igt_pipe_crc_t *pipe_crc, igt_crc_t *out)
>  	if (bytes_read > 0 && !pipe_crc_init_from_string(pipe_crc, out, buf))
>  		return -EINVAL;
>  
> +	crc_sanity_checks(pipe_crc, out);
> +
>  	return bytes_read;
>  }
>  
> @@ -885,27 +907,6 @@ igt_pipe_crc_get_crcs(igt_pipe_crc_t *pipe_crc, int n_crcs,
>  	return n;
>  }
>  
> -static void crc_sanity_checks(igt_pipe_crc_t *pipe_crc, igt_crc_t *crc)
> -{
> -	int i;
> -	bool all_zero = true;
> -
> -	/* Any CRC value can be considered valid on amdgpu hardware. */
> -	if (is_amdgpu_device(pipe_crc->fd))
> -		return;
> -
> -	for (i = 0; i < crc->n_words; i++) {
> -		igt_warn_on_f(crc->crc[i] == 0xffffffff,
> -			      "Suspicious CRC: it looks like the CRC "
> -			      "read back was from a register in a powered "
> -			      "down well\n");
> -		if (crc->crc[i])
> -			all_zero = false;
> -	}
> -
> -	igt_warn_on_f(all_zero, "Suspicious CRC: All values are 0.\n");
> -}
> -
>  /**
>   * igt_pipe_crc_drain:
>   * @pipe_crc: pipe CRC object
> @@ -946,8 +947,6 @@ 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 *crc)
>  {
>  	read_one_crc(pipe_crc, crc);
> -
> -	crc_sanity_checks(pipe_crc, crc);
>  }
>  
>  /**
> @@ -974,8 +973,6 @@ igt_pipe_crc_get_for_frame(int drm_fd, igt_pipe_crc_t *pipe_crc,
>  			return;
>  		}
>  	} while (igt_vblank_before(crc->frame, vblank));
> -
> -	crc_sanity_checks(pipe_crc, crc);
>  }
>  
>  /**