drm_common: enable specific device selection by means of path

DOCS/interface-changes.rst

@@ -27,6 +27,8 @@ Interface changes
 ::
 
  --- mpv 0.34.0 ---
+    - deprecate selecting by card number with `--drm-connector`, add
+      `--drm-device` which can be used instead
     - add `--screen-name` and `--fs-screen-name` flags to allow selecting the
       screen by its name instead of the index
     - add `--macos-geometry-calculation` to change the rectangle used for screen

DOCS/man/vo.rst

@@ -552,8 +552,13 @@ Available video output drivers are:
         Select the connector to use (usually this is a monitor.) If ``<name>``
         is empty or ``auto``, mpv renders the output on the first available
         connector. Use ``--drm-connector=help`` to get a list of available
-        connectors. When using multiple graphic cards, use the ``<gpu_number>``
-        argument to disambiguate.
+        connectors. The ``<gpu_number>`` argument can be used to disambiguate
+        multiple graphic cards, but is deprecated in favor of ``--drm-device``.
+        (default: empty)
+
+    ``--drm-device=<path>``
+        Select the DRM device file to use. If specified this overrides automatic
+        card selection and any card number specified ``--drm-connector``.
         (default: empty)
 
     ``--drm-mode=<preferred|highest|N|WxH[@R]>``

video/out/drm_common.c

@@ -74,6 +74,7 @@ static double mode_get_Hz(const drmModeModeInfo *mode);
 #define OPT_BASE_STRUCT struct drm_opts
 const struct m_sub_options drm_conf = {
     .opts = (const struct m_option[]) {
+        {"drm-device", OPT_STRING(drm_device_path), .flags = M_OPT_FILE},
         {"drm-connector", OPT_STRING(drm_connector_spec),
             .help = drm_connector_opt_help},
         {"drm-mode", OPT_STRING_VALIDATE(drm_mode_spec, drm_validate_mode_opt),
@@ -570,6 +571,8 @@ static void parse_connector_spec(struct mp_log *log,
     }
     char *dot_ptr = strchr(connector_spec, '.');
     if (dot_ptr) {
+        mp_warn(log, "Warning: Selecting a connector by index with drm-connector "
+                     "is deprecated. Use the drm-device option instead.\n");
         *card_no = atoi(connector_spec);
         *connector_name = talloc_strdup(log, dot_ptr + 1);
     } else {
@@ -578,15 +581,26 @@ static void parse_connector_spec(struct mp_log *log,
     }
 }
 
-struct kms *kms_create(struct mp_log *log, const char *connector_spec,
+struct kms *kms_create(struct mp_log *log,
+                       const char *drm_device_path,
+                       const char *connector_spec,
                        const char* mode_spec,
                        int draw_plane, int drmprime_video_plane,
                        bool use_atomic)
 {
     int card_no = -1;
     char *connector_name = NULL;
+
     parse_connector_spec(log, connector_spec, &card_no, &connector_name);
-    char *primary_node_path = get_primary_device_path(log, &card_no);
+    if (drm_device_path && card_no != -1)
+        mp_warn(log, "Both DRM device and card number (as part of "
+                     "drm-connector) are set! Will prefer given device path "
+                     "'%s'!\n",
+                drm_device_path);
+
+    char *primary_node_path = drm_device_path ?
+                              talloc_strdup(log, drm_device_path) :
+                              get_primary_device_path(log, &card_no);
 
     if (!primary_node_path) {
         mp_err(log,

video/out/drm_common.h

@@ -47,6 +47,7 @@ struct vt_switcher {
 };
 
 struct drm_opts {
+    char *drm_device_path;
     char *drm_connector_spec;
     char *drm_mode_spec;
     int drm_atomic;
@@ -80,7 +81,9 @@ void vt_switcher_acquire(struct vt_switcher *s, void (*handler)(void*),
 void vt_switcher_release(struct vt_switcher *s, void (*handler)(void*),
                          void *user_data);
 
-struct kms *kms_create(struct mp_log *log, const char *connector_spec,
+struct kms *kms_create(struct mp_log *log,
+                       const char *drm_device_path,
+                       const char *connector_spec,
                        const char *mode_spec,
                        int draw_plane, int drmprime_video_plane,
                        bool use_atomic);

video/out/opengl/context_drm_egl.c

@@ -732,7 +732,9 @@ static bool drm_egl_init(struct ra_ctx *ctx)
     }
 
     MP_VERBOSE(ctx, "Initializing KMS\n");
-    p->kms = kms_create(ctx->log, ctx->vo->opts->drm_opts->drm_connector_spec,
+    p->kms = kms_create(ctx->log,
+                        ctx->vo->opts->drm_opts->drm_device_path,
+                        ctx->vo->opts->drm_opts->drm_connector_spec,
                         ctx->vo->opts->drm_opts->drm_mode_spec,
                         ctx->vo->opts->drm_opts->drm_draw_plane,
                         ctx->vo->opts->drm_opts->drm_drmprime_video_plane,

video/out/vo_drm.c

@@ -566,6 +566,7 @@ static int preinit(struct vo *vo)
     }
 
     p->kms = kms_create(vo->log,
+                        vo->opts->drm_opts->drm_device_path,
                         vo->opts->drm_opts->drm_connector_spec,
                         vo->opts->drm_opts->drm_mode_spec,
                         0, 0, false);