Revert "drm: kms_helper: don't lose hotplug event"

This reverts commit 160954b7bca43da7cd3cfbce310e6df919a8216e.

This was rearming the workqueue with a 0 timeout, causing
a WARN_ON, and possible loop.

Daniel writes:
"I've looked a bit into this and I think we need to have a separate
work struct for recovering these lost hotplug events since the
continuous self-rearming case is a real risk (e.g. if a connector
flip-flops all the time). At least I don't see a sane way to block out
re-arming with the current code in a simple way. So reverting the
offender seems like the right thing and I'll go back to the drawing
board for 3.12."

Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 1 insertions, 32 deletions

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index f6829ba58e86..738a4294d820 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -122,7 +122,6 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
         int count = 0;
         int mode_flags = 0;
         bool verbose_prune = true;
-        enum drm_connector_status old_status;
 
         DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
                         drm_get_connector_name(connector));
@@ -138,32 +137,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
                 if (connector->funcs->force)
                         connector->funcs->force(connector);
         } else {
-                old_status = connector->status;
-
                 connector->status = connector->funcs->detect(connector, true);
-
-                /*
-                 * Normally either the driver's hpd code or the poll loop should
-                 * pick up any changes and fire the hotplug event. But if
-                 * userspace sneaks in a probe, we might miss a change. Hence
-                 * check here, and if anything changed start the hotplug code.
-                 */
-                if (old_status != connector->status) {
-                        DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
-                                      connector->base.id,
-                                      drm_get_connector_name(connector),
-                                      old_status, connector->status);
-
-                        /*
-                         * The hotplug event code might call into the fb
-                         * helpers, and so expects that we do not hold any
-                         * locks. Fire up the poll struct instead, it will
-                         * disable itself again.
-                         */
-                        dev->mode_config.delayed_event = true;
-                        schedule_delayed_work(&dev->mode_config.output_poll_work,
-                                              0);
-                }
         }
 
         /* Re-enable polling in case the global poll config changed. */
@@ -1011,11 +985,7 @@ static void output_poll_execute(struct work_struct *work)
         struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
         struct drm_connector *connector;
         enum drm_connector_status old_status;
-        bool repoll = false, changed;
-
-        /* Pick up any changes detected by the probe functions. */
-        changed = dev->mode_config.delayed_event;
-        dev->mode_config.delayed_event = false;
+        bool repoll = false, changed = false;
 
         if (!drm_kms_helper_poll)
                 return;
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 663c3ab47752..fa12a2fa4293 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -811,7 +811,6 @@ struct drm_mode_config {
         /* output poll support */
         bool poll_enabled;
         bool poll_running;
-        bool delayed_event;
         struct delayed_work output_poll_work;
 
         /* pointers to standard properties */