drm: Lighten sysfs connector 'status'

Since the beginning, sysfs/connector/status has done a heavyweight
detection of the current connector status. But no user, such as upowerd
or logind, has ever desired to initiate a probe. Move the probing into a
new attribute so that existing readers get the behaviour they desire.

v2: David Herrmann suggested using "echo detect > /sys/.../status" to
trigger the probing, which is a fine idea. This extends that to also
allow the user to apply the force detection overrides at runtime.

v3: Now with airlied's email address fixed! Requires sysfs_streq()

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
index 5c99d3773212a92928fb31c2b198f440a6e6a0b4..ffc305fc20768c29af6883eeb2d70553839cfa6e 100644 (file)
--- a/drivers/gpu/drm/drm_sysfs.c
+++ b/drivers/gpu/drm/drm_sysfs.c
@@ -166,23 +166,68 @@ void drm_sysfs_destroy(void)
 /*
  * Connector properties
  */
-static ssize_t status_show(struct device *device,
+static ssize_t status_store(struct device *device,
                           struct device_attribute *attr,
-                          char *buf)
+                          const char *buf, size_t count)
 {
        struct drm_connector *connector = to_drm_connector(device);
-       enum drm_connector_status status;
+       struct drm_device *dev = connector->dev;
+       enum drm_connector_status old_status;
        int ret;
 
-       ret = mutex_lock_interruptible(&connector->dev->mode_config.mutex);
+       ret = mutex_lock_interruptible(&dev->mode_config.mutex);
        if (ret)
                return ret;
 
-       status = connector->funcs->detect(connector, true);
-       mutex_unlock(&connector->dev->mode_config.mutex);
+       old_status = connector->status;
+
+       if (sysfs_streq(buf, "detect")) {
+               connector->force = 0;
+               connector->status = connector->funcs->detect(connector, true);
+       } else if (sysfs_streq(buf, "on")) {
+               connector->force = DRM_FORCE_ON;
+       } else if (sysfs_streq(buf, "on-digital")) {
+               connector->force = DRM_FORCE_ON_DIGITAL;
+       } else if (sysfs_streq(buf, "off")) {
+               connector->force = DRM_FORCE_OFF;
+       } else
+               ret = -EINVAL;
+
+       if (ret == 0 && connector->force) {
+               if (connector->force == DRM_FORCE_ON ||
+                   connector->force == DRM_FORCE_ON_DIGITAL)
+                       connector->status = connector_status_connected;
+               else
+                       connector->status = connector_status_disconnected;
+               if (connector->funcs->force)
+                       connector->funcs->force(connector);
+       }
+
+       if (old_status != connector->status) {
+               DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
+                             connector->base.id,
+                             connector->name,
+                             old_status, connector->status);
+
+               dev->mode_config.delayed_event = true;
+               if (dev->mode_config.poll_enabled)
+                       schedule_delayed_work(&dev->mode_config.output_poll_work,
+                                             0);
+       }
+
+       mutex_unlock(&dev->mode_config.mutex);
+
+       return ret;
+}
+
+static ssize_t status_show(struct device *device,
+                          struct device_attribute *attr,
+                          char *buf)
+{
+       struct drm_connector *connector = to_drm_connector(device);
 
        return snprintf(buf, PAGE_SIZE, "%s\n",
-                       drm_get_connector_status_name(status));
+                       drm_get_connector_status_name(connector->status));
 }
 
 static ssize_t dpms_show(struct device *device,
@@ -339,7 +384,7 @@ static ssize_t select_subconnector_show(struct device *device,
                        drm_get_dvi_i_select_name((int)subconnector));
 }
 
-static DEVICE_ATTR_RO(status);
+static DEVICE_ATTR_RW(status);
 static DEVICE_ATTR_RO(enabled);
 static DEVICE_ATTR_RO(dpms);
 static DEVICE_ATTR_RO(modes);