modesetting: add dynamic connector hotplug support (MST) (v3)

This is ported from the same code in the ati and intel drivers,

It uses the same option name as nvidia and the other DDXes to
disable tearing down outputs as it is hard to avoid racing with clients.

v2: address two issues with DeleteUnusedDP12 enabled, reported
by Daniel Martin,
a) check we have a mode_output before destroying it
b) only delete *unused* displays (thanks Aaron for clarifying)
so we check if the output has a crtc and if it does we don't
delete it.

v3: drop the option to delete unused displays, just encode
behaviour into the randr spec.
Signed-off-by: Dave Airlie <airlied@redhat.com>

hw/xfree86/drivers/modesetting/drmmode_display.c

@@ -326,6 +326,8 @@ drmmode_set_mode_major(xf86CrtcPtr crtc, DisplayModePtr mode,
                 continue;
 
             drmmode_output = output->driver_private;
+            if (drmmode_output->output_id == -1)
+                continue;
             output_ids[output_count] =
                 drmmode_output->mode_output->connector_id;
             output_count++;
@@ -366,10 +368,14 @@ drmmode_set_mode_major(xf86CrtcPtr crtc, DisplayModePtr mode,
         /* go through all the outputs and force DPMS them back on? */
         for (i = 0; i < xf86_config->num_output; i++) {
             xf86OutputPtr output = xf86_config->output[i];
+            drmmode_output_private_ptr drmmode_output;
 
             if (output->crtc != crtc)
                 continue;
 
+            drmmode_output = output->driver_private;
+            if (drmmode_output->output_id == -1)
+                continue;
             output->funcs->dpms(output, DPMSModeOn);
         }
     }
@@ -712,6 +718,9 @@ drmmode_output_detect(xf86OutputPtr output)
     drmmode_ptr drmmode = drmmode_output->drmmode;
     xf86OutputStatus status;
 
+    if (drmmode_output->output_id == -1)
+        return XF86OutputStatusDisconnected;
+
     drmModeFreeConnector(drmmode_output->mode_output);
 
     drmmode_output->mode_output =
@@ -873,11 +882,13 @@ drmmode_output_destroy(xf86OutputPtr output)
         free(drmmode_output->props[i].atoms);
     }
     free(drmmode_output->props);
-    for (i = 0; i < drmmode_output->mode_output->count_encoders; i++) {
-        drmModeFreeEncoder(drmmode_output->mode_encoders[i]);
+    if (drmmode_output->mode_output) {
+        for (i = 0; i < drmmode_output->mode_output->count_encoders; i++) {
+            drmModeFreeEncoder(drmmode_output->mode_encoders[i]);
+        }
+        drmModeFreeConnector(drmmode_output->mode_output);
     }
     free(drmmode_output->mode_encoders);
-    drmModeFreeConnector(drmmode_output->mode_output);
     free(drmmode_output);
     output->driver_private = NULL;
 }
@@ -1111,22 +1122,134 @@ static const char *const output_names[] = {
     "DSI",
 };
 
+static xf86OutputPtr find_output(ScrnInfoPtr pScrn, int id)
+{
+    xf86CrtcConfigPtr   xf86_config = XF86_CRTC_CONFIG_PTR(pScrn);
+    int i;
+    for (i = 0; i < xf86_config->num_output; i++) {
+        xf86OutputPtr output = xf86_config->output[i];
+        drmmode_output_private_ptr drmmode_output;
+
+        drmmode_output = output->driver_private;
+        if (drmmode_output->output_id == id)
+            return output;
+    }
+    return NULL;
+}
+
+static int parse_path_blob(drmModePropertyBlobPtr path_blob, int *conn_base_id, char **path)
+{
+    char *conn;
+    char conn_id[5];
+    int id, len;
+    char *blob_data;
+
+    if (!path_blob)
+        return -1;
+
+    blob_data = path_blob->data;
+    /* we only handle MST paths for now */
+    if (strncmp(blob_data, "mst:", 4))
+        return -1;
+
+    conn = strchr(blob_data + 4, '-');
+    if (!conn)
+        return -1;
+    len = conn - (blob_data + 4);
+    if (len + 1> 5)
+        return -1;
+    memcpy(conn_id, blob_data + 4, len);
+    conn_id[len + 1] = '\0';
+    id = strtoul(conn_id, NULL, 10);
+
+    *conn_base_id = id;
+
+    *path = conn + 1;
+    return 0;
+}
+
+static void
+drmmode_create_name(ScrnInfoPtr pScrn, drmModeConnectorPtr koutput, char *name,
+		    drmModePropertyBlobPtr path_blob)
+{
+    int ret;
+    char *extra_path;
+    int conn_id;
+    xf86OutputPtr output;
+
+    ret = parse_path_blob(path_blob, &conn_id, &extra_path);
+    if (ret == -1)
+        goto fallback;
+
+    output = find_output(pScrn, conn_id);
+    if (!output)
+        goto fallback;
+
+    snprintf(name, 32, "%s-%s", output->name, extra_path);
+    return;
+
+ fallback:
+    if (koutput->connector_type >= MS_ARRAY_SIZE(output_names))
+        snprintf(name, 32, "Unknown-%d", koutput->connector_type_id - 1);
+#ifdef MODESETTING_OUTPUT_SLAVE_SUPPORT
+    else if (pScrn->is_gpu)
+        snprintf(name, 32, "%s-%d-%d", output_names[koutput->connector_type], pScrn->scrnIndex - GPU_SCREEN_OFFSET + 1, koutput->connector_type_id - 1);
+#endif
+    else
+        snprintf(name, 32, "%s-%d", output_names[koutput->connector_type], koutput->connector_type_id - 1);
+}
+
 static void
-drmmode_output_init(ScrnInfoPtr pScrn, drmmode_ptr drmmode, drmModeResPtr mode_res, int num)
+drmmode_output_init(ScrnInfoPtr pScrn, drmmode_ptr drmmode, drmModeResPtr mode_res, int num, Bool dynamic)
 {
     xf86OutputPtr output;
+    xf86CrtcConfigPtr   xf86_config = XF86_CRTC_CONFIG_PTR(pScrn);
     drmModeConnectorPtr koutput;
     drmModeEncoderPtr *kencoders = NULL;
     drmmode_output_private_ptr drmmode_output;
     drmModePropertyPtr props;
     char name[32];
     int i;
+    drmModePropertyBlobPtr path_blob = NULL;
 
     koutput =
         drmModeGetConnector(drmmode->fd, mode_res->connectors[num]);
     if (!koutput)
         return;
 
+    for (i = 0; i < koutput->count_props; i++) {
+        props = drmModeGetProperty(drmmode->fd, koutput->props[i]);
+        if (props && (props->flags & DRM_MODE_PROP_BLOB)) {
+            if (!strcmp(props->name, "PATH")) {
+                path_blob = drmModeGetPropertyBlob(drmmode->fd, koutput->prop_values[i]);
+                drmModeFreeProperty(props);
+                break;
+            }
+            drmModeFreeProperty(props);
+        }
+    }
+
+    drmmode_create_name(pScrn, koutput, name, path_blob);
+
+    if (path_blob)
+        drmModeFreePropertyBlob(path_blob);
+
+    if (path_blob && dynamic) {
+        /* see if we have an output with this name already
+           and hook stuff up */
+        for (i = 0; i < xf86_config->num_output; i++) {
+            output = xf86_config->output[i];
+
+            if (strncmp(output->name, name, 32))
+                continue;
+
+            drmmode_output = output->driver_private;
+            drmmode_output->output_id = mode_res->connectors[num];
+            drmmode_output->mode_output = koutput;
+            return;
+        }
+    }
+
     kencoders = calloc(sizeof(drmModeEncoderPtr), koutput->count_encoders);
     if (!kencoders) {
         goto out_free_encoders;
@@ -1139,17 +1262,6 @@ drmmode_output_init(ScrnInfoPtr pScrn, drmmode_ptr drmmode, drmModeResPtr mode_r
         }
     }
 
-    /* need to do smart conversion here for compat with non-kms ATI driver */
-    if (koutput->connector_type >= MS_ARRAY_SIZE(output_names))
-        snprintf(name, 32, "Unknown-%d", koutput->connector_type_id - 1);
-    else if (pScrn->is_gpu)
-        snprintf(name, 32, "%s-%d-%d", output_names[koutput->connector_type],
-                 pScrn->scrnIndex - GPU_SCREEN_OFFSET + 1,
-                 koutput->connector_type_id - 1);
-    else
-        snprintf(name, 32, "%s-%d", output_names[koutput->connector_type],
-                 koutput->connector_type_id - 1);
-
     output = xf86OutputCreate(pScrn, &drmmode_output_funcs, name);
     if (!output) {
         goto out_free_encoders;
@@ -1192,6 +1304,8 @@ drmmode_output_init(ScrnInfoPtr pScrn, drmmode_ptr drmmode, drmModeResPtr mode_r
         }
     }
 
+    if (dynamic)
+        output->randr_output = RROutputCreate(xf86ScrnToScreen(pScrn), output->name, strlen(output->name), output);
     return;
  out_free_encoders:
     if (kencoders) {
@@ -1451,7 +1565,7 @@ drmmode_pre_init(ScrnInfoPtr pScrn, drmmode_ptr drmmode, int cpp)
             drmmode_crtc_init(pScrn, drmmode, mode_res, i);
 
     for (i = 0; i < mode_res->count_connectors; i++)
-        drmmode_output_init(pScrn, drmmode, mode_res, i);
+        drmmode_output_init(pScrn, drmmode, mode_res, i, FALSE);
 
     /* workout clones */
     drmmode_clones_init(pScrn, drmmode, mode_res);
@@ -1620,11 +1734,78 @@ drmmode_handle_uevents(int fd, void *closure)
     drmmode_ptr drmmode = closure;
     ScrnInfoPtr scrn = drmmode->scrn;
     struct udev_device *dev;
+    drmModeResPtr mode_res;
+    xf86CrtcConfigPtr  config = XF86_CRTC_CONFIG_PTR(scrn);
+    int i, j;
+    Bool found;
+    Bool changed = FALSE;
 
     dev = udev_monitor_receive_device(drmmode->uevent_monitor);
     if (!dev)
         return;
 
+    mode_res = drmModeGetResources(drmmode->fd);
+    if (!mode_res)
+        goto out;
+
+    if (mode_res->count_crtcs != config->num_crtc) {
+        ErrorF("number of CRTCs changed - failed to handle, %d vs %d\n", mode_res->count_crtcs, config->num_crtc);
+        goto out_free_res;
+    }
+
+    /* figure out if we have gotten rid of any connectors
+       traverse old output list looking for outputs */
+    for (i = 0; i < config->num_output; i++) {
+        xf86OutputPtr output = config->output[i];
+        drmmode_output_private_ptr drmmode_output;
+
+        drmmode_output = output->driver_private;
+        found = FALSE;
+        for (j = 0; j < mode_res->count_connectors; j++) {
+            if (mode_res->connectors[j] == drmmode_output->output_id) {
+                found = TRUE;
+                break;
+            }
+        }
+        if (found)
+            continue;
+
+        drmModeFreeConnector(drmmode_output->mode_output);
+        drmmode_output->mode_output = NULL;
+        drmmode_output->output_id = -1;
+
+        changed = TRUE;
+    }
+
+    /* find new output ids we don't have outputs for */
+    for (i = 0; i < mode_res->count_connectors; i++) {
+        found = FALSE;
+
+        for (j = 0; j < config->num_output; j++) {
+            xf86OutputPtr output = config->output[j];
+            drmmode_output_private_ptr drmmode_output;
+
+            drmmode_output = output->driver_private;
+            if (mode_res->connectors[i] == drmmode_output->output_id) {
+                found = TRUE;
+                break;
+            }
+        }
+        if (found)
+            continue;
+
+        changed = TRUE;
+        drmmode_output_init(scrn, drmmode, mode_res, i, 1);
+    }
+
+    if (changed) {
+        RRSetChanged(xf86ScrnToScreen(scrn));
+        RRTellChanged(xf86ScrnToScreen(scrn));
+    }
+
+out_free_res:
+    drmModeFreeResources(mode_res);
+out:
     RRGetInfo(xf86ScrnToScreen(scrn), TRUE);
     udev_device_unref(dev);
 }