Re: [igt-dev] [PATCH i-g-t 1/2] lib/igt_debugfs: added helper to enable/disable dark screen detection

[Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>]

On 15.11.2023 8.42, Kunal Joshi wrote:
> added helper function for dark screen detection
> 
> v2: Fix indentation (JP)
>      Reduce complexity and redundancy (JP)
> 
> Cc: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
> Cc: Nemesa Garg <nemesa.garg@intel.com>
> Cc: Arun R Murthy <arun.r.murthy@intel.com>
> Cc: Bhanuprakash Modem <bhanuprakash.modem@intel.com>
> Signed-off-by: Kunal Joshi <kunal1.joshi@intel.com>
> Signed-off-by: Kunal Joshi <kunal1.joshi@intel.com>
> ---
>   lib/igt_debugfs.c | 23 +++++++++++++++++++++++
>   lib/igt_debugfs.h |  2 ++
>   2 files changed, 25 insertions(+)
> 
> diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c
> index a7b54bae5..c4a8b532d 100644
> --- a/lib/igt_debugfs.c
> +++ b/lib/igt_debugfs.c
> @@ -743,3 +743,26 @@ void __igt_debugfs_dump(int device, const char *filename, int level)
>   	igt_log(IGT_LOG_DOMAIN, level, "%s:\n%s\n", filename, contents);
>   	free(contents);
>   }
> +
> +bool igt_is_dark_screen_supported(int drm_fd, enum pipe pipe)
> +{
> +	char buf[256];
> +	int dir;
> +
> +	dir = igt_debugfs_pipe_dir(drm_fd, pipe, O_DIRECTORY);
> +	igt_require_fd(dir);
> +	igt_debugfs_simple_read(dir, "i915_darkscreen_status", buf, sizeof(buf));
> +	close(dir);
> +	return (*buf == '0' || *buf == '1');
> +}
> +
> +ssize_t igt_set_dark_screen_detection(int drm_fd, enum pipe pipe, bool enable)
> +{
> +	char buf[2];
> +	int dir;
> +
> +	snprintf(buf, sizeof(buf), "%d", enable ? 1 : 0);
> +	dir = igt_debugfs_pipe_dir(drm_fd, pipe, O_DIRECTORY);
> +	igt_require_fd(dir);
> +	return igt_sysfs_write(dir, "i915_darkscreen_status", buf, sizeof(buf) - 1);

Would something like
igt_sysfs_write(dir, "i915_darkscreen_status", enable ? "1" : "0", 1);
work?

Also I think you'll need to close dir before return

/Juha-Pekka

> +}
> diff --git a/lib/igt_debugfs.h b/lib/igt_debugfs.h
> index 3e6194ade..68f25be59 100644
> --- a/lib/igt_debugfs.h
> +++ b/lib/igt_debugfs.h
> @@ -77,6 +77,8 @@ void igt_hpd_storm_reset(int fd);
>   bool igt_hpd_storm_detected(int fd);
>   void igt_require_hpd_storm_ctl(int fd);
>   bool igt_ignore_long_hpd(int fd, bool enable);
> +bool igt_is_dark_screen_supported(int drm_fd, enum pipe pipe);
> +ssize_t igt_set_dark_screen_detection(int drm_fd, enum pipe pipe, bool enable);
>   
>   /*
>    * Drop caches