Re: [igt-dev] [PATCH i-g-t 2/4] lib/igt_kms: add helper for dp-mst connector id

["Modem, Bhanuprakash" <bhanuprakash.modem@intel.com>]

Hi Swati,

On Sun-06-08-2023 10:17 pm, Swati Sharma wrote:
> Helper is added which returns dp-mst connector id.
> 
> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
> ---
>   lib/igt_kms.c | 40 ++++++++++++++++++++++++++++++++++++++++
>   lib/igt_kms.h |  1 +
>   2 files changed, 41 insertions(+)
> 
> diff --git a/lib/igt_kms.c b/lib/igt_kms.c
> index 6034ff70c..c0bfa73fe 100644
> --- a/lib/igt_kms.c
> +++ b/lib/igt_kms.c
> @@ -6050,3 +6050,43 @@ bool igt_check_output_is_dp_mst(int drm_fd, igt_output_t *output)
>   
>   	return true;
>   }
> +
> +static int parse_path_blob(char *blob_data)
> +{
> +	int connector_id;
> +	char *encoder;
> +
> +	encoder = strtok(blob_data, ":");
> +	igt_assert_f(!strcmp(encoder, "mst"), "PATH connector property expected to have 'mst'\n");
> +
> +	connector_id = atoi(strtok(NULL, "-"));
> +
> +	return connector_id;
> +}
> +
> +/**
> + * igt_get_dp_mst_connector_id
> + * @drmfd: Handle to open drm device
> + * @output: Target output
> + *
> + * Returns: dp-mst connector id.
> + */
> +int igt_get_dp_mst_connector_id(int drm_fd, igt_output_t *output)
> +{
> +	drmModePropertyBlobPtr path_blob = NULL;
> +	uint64_t path_blob_id;
> +	drmModeConnector *connector = output->config.connector;
> +	int connector_id;
> +
> +	igt_assert(kmstest_get_property(drm_fd, connector->connector_id,
> +		   DRM_MODE_OBJECT_CONNECTOR, "PATH", NULL,
> +		   &path_blob_id, NULL));
> +
> +	igt_assert(path_blob = drmModeGetPropertyBlob(drm_fd, path_blob_id));
> +
> +	connector_id = parse_path_blob((char *) path_blob->data);
> +
> +	drmModeFreePropertyBlob(path_blob);
> +
> +	return connector_id;

I can write this helper as:

int igt_get_dp_mst_connector_id() {
     if igt_check_output_is_dp_mst()
         return 0; // Not sure if connector_id can be zero

     <get PATH property & parse the connector id outof it>
     return connector_id;
}

Test:
You can directly call igt_get_dp_mst_connector_id(), no need to check 
for the output type (dp-mst).

- Bhanu

> +}
> diff --git a/lib/igt_kms.h b/lib/igt_kms.h
> index 9a46e7a5c..6f978ed55 100644
> --- a/lib/igt_kms.h
> +++ b/lib/igt_kms.h
> @@ -1005,5 +1005,6 @@ bool igt_check_bigjoiner_support(igt_display_t *display);
>   bool igt_parse_mode_string(const char *mode_string, drmModeModeInfo *mode);
>   bool i915_pipe_output_combo_valid(igt_display_t *display);
>   bool igt_check_output_is_dp_mst(int drmfd, igt_output_t *output);
> +int igt_get_dp_mst_connector_id(int drm_fd, igt_output_t *output);
>   
>   #endif /* __IGT_KMS_H__ */