[Intel-gfx] [PATCH i-g-t] intel_display_crc: A new tool to play with display CRCs

[Daniel Vetter]

On Thu, May 14, 2015 at 03:39:50PM +0100, Damien Lespiau wrote:
> The CRC debug interface is a bit more than a simple textual file in
> debugfs as there are a small command language to control what we want
> from them.
> 
> This tool starts, slowly, by allowing us to dump the pipe CRCs whenever
> we want. It can be handy to check what is the current CRC when we reach
> a certain state on the screen (when using --interactive-debug for
> instance) against a known CRC.
> 
> Signed-off-by: Damien Lespiau <damien.lespiau at intel.com>

Right now the kernel has only one fifo and multiple consumers will eat
away each anothers CRCs. My gut feeling is that extending the debug loggin
in igt_debugfs.c would be more useful. Or maybe we need to juggle things
around a bit and have a per open fd read pointer in the kernel into the
crc ringbuffer?
-Daniel

> ---
>  tools/.gitignore          |   1 +
>  tools/Makefile.sources    |   1 +
>  tools/intel_display_crc.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 112 insertions(+)
>  create mode 100644 tools/intel_display_crc.c
> 
> diff --git a/tools/.gitignore b/tools/.gitignore
> index b47fafd..5a2f5ff 100644
> --- a/tools/.gitignore
> +++ b/tools/.gitignore
> @@ -4,6 +4,7 @@ intel_audio_dump
>  intel_backlight
>  intel_bios_dumper
>  intel_bios_reader
> +intel_display_crc
>  intel_display_poller
>  intel_dump_decode
>  intel_error_decode
> diff --git a/tools/Makefile.sources b/tools/Makefile.sources
> index b07a71c..5acf45a 100644
> --- a/tools/Makefile.sources
> +++ b/tools/Makefile.sources
> @@ -10,6 +10,7 @@ bin_PROGRAMS = 				\
>  	intel_backlight 		\
>  	intel_bios_dumper 		\
>  	intel_bios_reader 		\
> +	intel_display_crc		\
>  	intel_display_poller		\
>  	intel_dump_decode 		\
>  	intel_error_decode 		\
> diff --git a/tools/intel_display_crc.c b/tools/intel_display_crc.c
> new file mode 100644
> index 0000000..ba9ec5b
> --- /dev/null
> +++ b/tools/intel_display_crc.c
> @@ -0,0 +1,110 @@
> +/*
> + * Copyright © 2015 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + *    Damien Lespiau <damien.lespiau at intel.com>
> + */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +
> +#include "igt_core.h"
> +#include "igt_debugfs.h"
> +#include "igt_kms.h"
> +
> +typedef struct {
> +	int fd;
> +	int pipe;
> +	int n_crcs;
> +} display_crc_t;
> +
> +static int pipe_from_str(const char *str)
> +{
> +	unsigned char c;
> +
> +	if (!str || strlen(str) != 1)
> +		return -1;
> +
> +	c = str[0];
> +
> +	if (c >= 'A' && c <= 'C')
> +		return c - 'A';
> +
> +	if (c >= 'a' && c <= 'c')
> +		return c - 'a';
> +
> +	if (c >= '0' && c <= '3')
> +		return c - '0';
> +
> +	return -1;
> +}
> +
> +static void print_crcs(display_crc_t *ctx)
> +{
> +	igt_pipe_crc_t *pipe_crc;
> +	igt_crc_t crc;
> +	char *crc_str;
> +	int i;
> +
> +	pipe_crc = igt_pipe_crc_new(ctx->pipe, INTEL_PIPE_CRC_SOURCE_AUTO);
> +
> +	for (i = 0; i < ctx->n_crcs; i++) {
> +		igt_pipe_crc_collect_crc(pipe_crc, &crc);
> +
> +		crc_str = igt_crc_to_string(&crc);
> +		printf("CRC on pipe %s: %s\n", kmstest_pipe_name(ctx->pipe),
> +		       crc_str);
> +		free(crc_str);
> +	}
> +
> +	igt_pipe_crc_free(pipe_crc);
> +}
> +
> +static display_crc_t ctx;
> +
> +int main(int argc, char **argv)
> +{
> +	int opt;
> +
> +	ctx.n_crcs = 1;
> +
> +	while ((opt = getopt(argc, argv, "p:n:")) != -1) {
> +		switch (opt) {
> +		case 'p':
> +			ctx.pipe = pipe_from_str(optarg);
> +			if (ctx.pipe == -1) {
> +				fprintf(stderr, "Unknown pipe %s\n", optarg);
> +				exit(1);
> +			}
> +			break;
> +		case 'n':
> +			ctx.n_crcs = atoi(optarg);
> +			break;
> +		default:
> +			igt_assert(0);
> +		}
> +	}
> +
> +	print_crcs(&ctx);
> +}
> -- 
> 2.1.0
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch