Re: [PATCH i-g-t] tests/kms_bw: Skip tests when outputs don't support the mode

[Louis Chauvet <louis.chauvet@bootlin.com>]

On 2/25/26 17:03, Jason-JH Lin wrote:
> The kms_bw test uses hardcoded display timings that may not match
> what connected panels support. This causes test failures when forcing
> unsupported modes on fixed-mode panels like DSI.
> 
> Add output_mode_supported() to check if a mode exists in the
> connector's mode list before using it. Skip outputs that don't
> support the requested mode during buffer creation, CRC collection,
> and cleanup.
> 
> For multi-output tests, proceed if at least one output supports
> the mode. Skip only if all outputs reject it.
> 
> Signed-off-by: Jason-JH Lin <jason-jh.lin@mediatek.com>
> ---
>   tests/kms_bw.c | 39 +++++++++++++++++++++++++++++++++++----
>   1 file changed, 35 insertions(+), 4 deletions(-)
> 
> diff --git a/tests/kms_bw.c b/tests/kms_bw.c
> index 778900d8c9f1..dc79ccc001f1 100644
> --- a/tests/kms_bw.c
> +++ b/tests/kms_bw.c
> @@ -187,6 +187,35 @@ static void force_output_mode(data_t *d, igt_output_t *output,
>   	igt_output_override_mode(output, mode);
>   }
>   
> +static bool output_mode_supported(igt_output_t *output, const drmModeModeInfo *mode)
> +{
> +	drmModeConnector *connector = output->config.connector;
> +	int i;
> +
> +	/* Virtual/forced sinks support all modes */
> +	if (!igt_output_is_connected(output))
> +		return true;> +	for (i = 0; i < connector->count_modes; i++) {
> +		drmModeModeInfo *conn_mode = &connector->modes[i];
> +
> +		if (conn_mode->hdisplay == mode->hdisplay &&
> +		    conn_mode->vdisplay == mode->vdisplay &&
> +		    conn_mode->vrefresh == mode->vrefresh) {
> +			igt_info("Found matching mode for %dx%d@%dHz on %s\n",
> +				 mode->hdisplay, mode->vdisplay, mode->vrefresh,
> +				 igt_output_name(output));

Hello,

I think this should be a igt_debug, I don't think this is useful to see 
it every time in normal operations.

With or without this:
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>

Thanks,
Louis Chauvet

> +			return true;
> +		}
> +	}
> +
> +	igt_info("Mode %dx%d@%dHz not supported by %s (has %d modes)\n",
> +		 mode->hdisplay, mode->vdisplay, mode->vrefresh,
> +		 igt_output_name(output), connector->count_modes);
> +
> +	return false;
> +}
> +
>   static void run_test_linear_tiling(data_t *data, int pipe, const drmModeModeInfo *mode, bool physical) {
>   	igt_display_t *display = &data->display;
>   	igt_output_t *output;
> @@ -194,7 +223,7 @@ static void run_test_linear_tiling(data_t *data, int pipe, const drmModeModeInfo
>   	igt_crc_t zero, captured[IGT_MAX_PIPES];
>   	int i = 0, num_pipes = 0;
>   	igt_crtc_t *crtc;
> -	int ret;
> +	int ret = -EINVAL;
>   
>   	/* Cannot use igt_display_n_crtcs() due to fused pipes on i915 where they do
>   	 * not give the numver of valid crtcs and always return IGT_MAX_PIPES */
> @@ -211,7 +240,7 @@ static void run_test_linear_tiling(data_t *data, int pipe, const drmModeModeInfo
>   	/* create buffers */
>   	for (i = 0; i <= pipe; i++) {
>   		output = physical ? data->connected_output[i] : data->output[i];
> -		if (!output) {
> +		if (!output || !output_mode_supported(output, mode)) {
>   			continue;
>   		}
>   
> @@ -228,7 +257,9 @@ static void run_test_linear_tiling(data_t *data, int pipe, const drmModeModeInfo
>   		igt_plane_set_fb(data->primary[i], &buffer[i]);
>   		igt_info("Assigning pipe %s to output %s with mode %s\n",
>   			 kmstest_pipe_name(i), igt_output_name(output), mode->name);
> +		ret = 0;
>   	}
> +	igt_skip_on_f(ret != 0, "Unsupported mode for all pipes\n");
 >
>   	ret = igt_display_try_commit_atomic(display,
>   					    DRM_MODE_ATOMIC_ALLOW_MODESET |
> @@ -240,7 +271,7 @@ static void run_test_linear_tiling(data_t *data, int pipe, const drmModeModeInfo
>   
>   	for (i = 0; i <= pipe; i++) {
>   		output = physical ? data->connected_output[i] : data->output[i];
> -		if (!output) {
> +		if (!output || !output_mode_supported(output, mode)) {
>   			continue;
>   		}
>   
> @@ -251,7 +282,7 @@ static void run_test_linear_tiling(data_t *data, int pipe, const drmModeModeInfo
>   
>   	for (i = pipe; i >= 0; i--) {
>   		output = physical ? data->connected_output[i] : data->output[i];
> -		if (!output)
> +		if (!output || !output_mode_supported(output, mode))
>   			continue;
>   
>   		igt_remove_fb(display->drm_fd, &buffer[i]);