compositor-drm: Handle unconnected connectors better

If a connector is not attached to a crtc, weston fails to bring it up.
Typically kms fbdev drives all crtc and connectors, but if kms hasn't been
initialzed and weston is the first to set a mode of if a monitor is
hotplugged, we just fail to bring it up.

(krh: reformatted and edited a bit from original patch)

diff --git a/src/compositor-drm.c b/src/compositor-drm.c
index bc75a00..cd0395e 100644 (file)
--- a/src/compositor-drm.c
+++ b/src/compositor-drm.c
@@ -1337,14 +1337,16 @@ create_output_for_connector(struct drm_compositor *ec,
        /* Get the current mode on the crtc that's currently driving
         * this connector. */
        encoder = drmModeGetEncoder(ec->drm.fd, connector->encoder_id);
-       if (encoder == NULL)
-               goto err_free;
-       crtc = drmModeGetCrtc(ec->drm.fd, encoder->crtc_id);
-       drmModeFreeEncoder(encoder);
-       if (crtc == NULL)
-               goto err_free;
-       crtc_mode = crtc->mode;
-       drmModeFreeCrtc(crtc);
+       memset(&crtc_mode, 0, sizeof crtc_mode);
+       if (encoder != NULL) {
+               crtc = drmModeGetCrtc(ec->drm.fd, encoder->crtc_id);
+               drmModeFreeEncoder(encoder);
+               if (crtc == NULL)
+                       goto err_free;
+               if (crtc->mode_valid)
+                       crtc_mode = crtc->mode;
+               drmModeFreeCrtc(crtc);
+       }
 
        for (i = 0; i < connector->count_modes; i++) {
                ret = drm_output_add_mode(output, &connector->modes[i]);
@@ -1355,34 +1357,34 @@ create_output_for_connector(struct drm_compositor *ec,
        preferred = NULL;
        current = NULL;
        wl_list_for_each(drm_mode, &output->base.mode_list, base.link) {
-               if (!memcmp(&crtc_mode, &drm_mode->mode_info, sizeof crtc_mode)) {
-                       drm_mode->base.flags |= WL_OUTPUT_MODE_CURRENT;
+               if (!memcmp(&crtc_mode, &drm_mode->mode_info, sizeof crtc_mode))
                        current = &drm_mode->base;
-               }
                if (drm_mode->base.flags & WL_OUTPUT_MODE_PREFERRED)
                        preferred = &drm_mode->base;
        }
 
-       if (current == NULL) {
+       if (current == NULL && crtc_mode.clock != 0) {
                ret = drm_output_add_mode(output, &crtc_mode);
                if (ret)
                        goto err_free;
                current = container_of(output->base.mode_list.prev,
                                       struct weston_mode, link);
-               current->flags |= WL_OUTPUT_MODE_CURRENT;
        }
 
-       if (preferred == NULL)
-               preferred = current;
-
-       if (option_current_mode) {
+       if (option_current_mode && current)
                output->base.current = current;
-       } else {
+       else if (preferred)
                output->base.current = preferred;
-               current->flags &= ~WL_OUTPUT_MODE_CURRENT;
-               preferred->flags |= WL_OUTPUT_MODE_CURRENT;
+       else if (current)
+               output->base.current = current;
+
+       if (output->base.current == NULL) {
+               weston_log("no available modes for %s\n", output->name);
+               goto err_free;
        }
 
+       output->base.current->flags |= WL_OUTPUT_MODE_CURRENT;
+
        output->surface = gbm_surface_create(ec->gbm,
                                             output->base.current->width,
                                             output->base.current->height,