Re: [PATCH i-g-t v2] tests/intel/kms_busy: Verify display reset happened

[Jani Nikula <jani.nikula@intel.com>]

On Mon, 13 Apr 2026, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Use the new "intel_display_reset_count" debugfs file to confirm that the
> kernel did in fact perform the display reset.
>
> v2: Give the file an "intel_" namespace (Jani)
>     Don't leak the debugfs dirfd
>
> Cc: Jani Nikula <jani.nikula@intel.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Seems reasonable.

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


> ---
>  tests/intel/kms_busy.c | 23 +++++++++++++++++++++--
>  1 file changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/tests/intel/kms_busy.c b/tests/intel/kms_busy.c
> index e82380276666..039cc6ae8dab 100644
> --- a/tests/intel/kms_busy.c
> +++ b/tests/intel/kms_busy.c
> @@ -35,6 +35,7 @@
>  
>  #include "i915/gem.h"
>  #include "igt.h"
> +#include "igt_sysfs.h"
>  
>  /**
>   * SUBTEST: basic
> @@ -413,6 +414,18 @@ static void gpu_engines_restore_timeouts(int fd, int num_engines, const struct g
>  		gem_engine_properties_restore(fd, &props[i]);
>  }
>  
> +static uint32_t display_reset_count(int drm_fd)
> +{
> +	uint32_t count;
> +	int dir;
> +
> +	dir = igt_debugfs_dir(drm_fd);
> +	count = igt_sysfs_get_u32(dir, "intel_display_reset_count");
> +	close(dir);
> +
> +	return count;
> +}
> +
>  const char *help_str =
>  	"  -e \tRun on all pipes. (By default subtests will run on two pipes)\n";
>  
> @@ -549,16 +562,22 @@ int igt_main_args("e", NULL, help_str, opt_handler, NULL)
>  					continue;
>  
>  				igt_dynamic_f("pipe-%s", igt_crtc_name(crtc)) {
> -					if (tests[i].reset)
> +					uint32_t reset_count_pre = 0;
> +
> +					if (tests[i].reset) {
>  						igt_set_module_param_int(display.drm_fd, "force_reset_modeset_test", 1);
> +						reset_count_pre = display_reset_count(display.drm_fd);
> +					}
>  
>  					test_hang(&display,
>  						  crtc,
>  						  output,
>  						  tests[i].modeset, tests[i].hang_newfb);
>  
> -					if (tests[i].reset)
> +					if (tests[i].reset) {
>  						igt_set_module_param_int(display.drm_fd, "force_reset_modeset_test", 0);
> +						igt_assert_neq(reset_count_pre, display_reset_count(display.drm_fd));
> +					}
>  				}
>  			}

-- 
Jani Nikula, Intel