[Intel-gfx] [PATCH i-g-t v2] tests/pm_backlight: Add backlight test

[Jani Nikula]

On Thu, 28 May 2015, Antti Koskipaa <antti.koskipaa at linux.intel.com> wrote:
> This is a basic sanity test of the backlight sysfs interface.
>
> v2:
>  - Add jani's suggestion for immediate readback
>  - Remove unused parameter from test_and_verify()
>  - Add fade test
>
> Issue: VIZ-3377
> Signed-off-by: Antti Koskipaa <antti.koskipaa at linux.intel.com>

Reviewed-by: Jani Nikula <jani.nikula at intel.com>


> ---
>  tests/.gitignore       |   1 +
>  tests/Makefile.sources |   1 +
>  tests/pm_backlight.c   | 171 +++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 173 insertions(+)
>  create mode 100644 tests/pm_backlight.c
>
> diff --git a/tests/.gitignore b/tests/.gitignore
> index a3f3143..f816ded 100644
> --- a/tests/.gitignore
> +++ b/tests/.gitignore
> @@ -150,6 +150,7 @@ kms_vblank
>  kms_crtc_background_color
>  kms_plane_scaling
>  kms_panel_fitting
> +pm_backlight
>  pm_lpsp
>  pm_rc6_residency
>  pm_rpm
> diff --git a/tests/Makefile.sources b/tests/Makefile.sources
> index 994c31b..d2a44e8 100644
> --- a/tests/Makefile.sources
> +++ b/tests/Makefile.sources
> @@ -80,6 +80,7 @@ TESTS_progs_M = \
>  	kms_crtc_background_color \
>  	kms_plane_scaling \
>  	kms_panel_fitting \
> +	pm_backlight \
>  	pm_lpsp \
>  	pm_rpm \
>  	pm_rps \
> diff --git a/tests/pm_backlight.c b/tests/pm_backlight.c
> new file mode 100644
> index 0000000..d02336d
> --- /dev/null
> +++ b/tests/pm_backlight.c
> @@ -0,0 +1,171 @@
> +/*
> + * 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.
> + *
> + * Author:
> + *    Antti Koskipaa <antti.koskipaa at linux.intel.com>
> + *
> + */
> +
> +#include <limits.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <fcntl.h>
> +#include <stdio.h>
> +#include <errno.h>
> +#include <unistd.h>
> +#include <time.h>
> +
> +#include "igt_core.h"
> +
> +#define TOLERANCE 5 /* percent */
> +#define BACKLIGHT_PATH "/sys/class/backlight/intel_backlight"
> +
> +#define FADESTEPS 10
> +#define FADESPEED 100 /* milliseconds between steps */
> +
> +IGT_TEST_DESCRIPTION("Basic backlight sysfs test");
> +
> +static int backlight_read(int *result, const char *fname)
> +{
> +	int fd;
> +	char full[PATH_MAX];
> +	char dst[64];
> +	int r, e;
> +
> +	igt_assert(snprintf(full, PATH_MAX, "%s/%s", BACKLIGHT_PATH, fname) < PATH_MAX);
> +
> +	fd = open(full, O_RDONLY);
> +	if (fd == -1)
> +		return -errno;
> +
> +	r = read(fd, dst, sizeof(dst));
> +	e = errno;
> +	close(fd);
> +
> +	if (r < 0)
> +		return -e;
> +
> +	errno = 0;
> +	*result = strtol(dst, NULL, 10);
> +	return errno;
> +}
> +
> +static int backlight_write(int value, const char *fname)
> +{
> +	int fd;
> +	char full[PATH_MAX];
> +	char src[64];
> +	int len;
> +
> +	igt_assert(snprintf(full, PATH_MAX, "%s/%s", BACKLIGHT_PATH, fname) < PATH_MAX);
> +	fd = open(full, O_WRONLY);
> +	if (fd == -1)
> +		return -errno;
> +
> +	len = snprintf(src, sizeof(src), "%i", value);
> +	len = write(fd, src, len);
> +	close(fd);
> +
> +	if (len < 0)
> +		return len;
> +
> +	return 0;
> +}
> +
> +static void test_and_verify(int val)
> +{
> +	int result;
> +
> +	igt_assert(backlight_write(val, "brightness") == 0);
> +	igt_assert(backlight_read(&result, "brightness") == 0);
> +	/* Check that the exact value sticks */
> +	igt_assert(result == val);
> +
> +	igt_assert(backlight_read(&result, "actual_brightness") == 0);
> +	/* Some rounding may happen depending on hw. Just check that it's close enough. */
> +	igt_assert(result <= val + val * TOLERANCE / 100 && result >= val - val * TOLERANCE / 100);
> +}
> +
> +static void test_brightness(int max)
> +{
> +	test_and_verify(0);
> +	test_and_verify(max);
> +	test_and_verify(max / 2);
> +}
> +
> +static void test_bad_brightness(int max)
> +{
> +	int val;
> +	/* First write some sane value */
> +	backlight_write(max / 2, "brightness");
> +	/* Writing invalid values should fail and not change the value */
> +	igt_assert(backlight_write(-1, "brightness") < 0);
> +	backlight_read(&val, "brightness");
> +	igt_assert(val == max / 2);
> +	igt_assert(backlight_write(max + 1, "brightness") < 0);
> +	backlight_read(&val, "brightness");
> +	igt_assert(val == max / 2);
> +	igt_assert(backlight_write(INT_MAX, "brightness") < 0);
> +	backlight_read(&val, "brightness");
> +	igt_assert(val == max / 2);
> +}
> +
> +static void test_fade(int max)
> +{
> +	int i;
> +	static const struct timespec ts = { .tv_sec = 0, .tv_nsec = FADESPEED*1000000 };
> +
> +	/* Fade out, then in */
> +	for (i = max; i > 0; i -= max / FADESTEPS) {
> +		test_and_verify(i);
> +		nanosleep(&ts, NULL);
> +	}
> +	for (i = 0; i <= max; i += max / FADESTEPS) {
> +		test_and_verify(i);
> +		nanosleep(&ts, NULL);
> +	}
> +}
> +
> +igt_main
> +{
> +	int max, old;
> +
> +	igt_skip_on_simulation();
> +
> +	igt_fixture {
> +		/* Get the max value and skip the whole test if sysfs interface not available */
> +		igt_skip_on(backlight_read(&old, "brightness"));
> +		igt_assert(backlight_read(&max, "max_brightness") > -1);
> +	}
> +
> +	igt_subtest("brightness")
> +		test_brightness(max);
> +	igt_subtest("bad-brightness")
> +		test_bad_brightness(max);
> +	igt_subtest("fade")
> +		test_fade(max);
> +
> +	igt_fixture {
> +		/* Restore old brightness */
> +		backlight_write(old, "brightness");
> +	}
> +}
> -- 
> 1.8.3.2
>

-- 
Jani Nikula, Intel Open Source Technology Center