From 6221d249d1f03d235a23a284c597c86676b32d2f Mon Sep 17 00:00:00 2001
From: David Herrmann <dh.herrmann@gmail.com>
Date: Sat, 20 Sep 2014 09:50:10 +0200
Subject: [PATCH] terminal: grdev: refresh device state on hotplug events

Whenever we get udev hotplug events, re-read the device state so we
properly detect any changed in the display setups.
---
 src/libsystemd-terminal/grdev-drm.c      | 32 +++++++++++++++++++++++++++++++-
 src/libsystemd-terminal/grdev-internal.h |  1 +
 src/libsystemd-terminal/grdev.c          |  2 +-
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/src/libsystemd-terminal/grdev-drm.c b/src/libsystemd-terminal/grdev-drm.c
index 3481584fbf..f0f0448635 100644
--- a/src/libsystemd-terminal/grdev-drm.c
+++ b/src/libsystemd-terminal/grdev-drm.c
@@ -2096,8 +2096,11 @@ static void grdrm_card_hotplug(grdrm_card *card) {
         int r;
 
         assert(card);
-        assert(!card->ready);
 
+        if (!card->running)
+                return;
+
+        card->ready = false;
         r = grdrm_card_resync(card);
         if (r < 0) {
                 log_debug("grdrm: %s/%s: cannot re-sync card: %s",
@@ -2955,3 +2958,30 @@ int grdev_drm_card_new(grdev_card **out, grdev_session *session, struct udev_dev
 
         return session->managed ? managed_card_new(out, session, ud) : unmanaged_card_new(out, session, ud);
 }
+
+void grdev_drm_card_hotplug(grdev_card *basecard, struct udev_device *ud) {
+        const char *p, *action;
+        grdrm_card *card;
+        dev_t devnum;
+
+        assert(basecard);
+        assert(grdev_is_drm_card(basecard));
+        assert(ud);
+
+        card = grdrm_card_from_base(basecard);
+
+        action = udev_device_get_action(ud);
+        if (!action || streq(action, "add") || streq(action, "remove")) {
+                /* If we get add/remove events on DRM nodes without devnum, we
+                 * got hotplugged DRM objects so refresh the device. */
+                devnum = udev_device_get_devnum(ud);
+                if (devnum == 0)
+                        grdrm_card_hotplug(card);
+        } else if (streq_ptr(action, "change")) {
+                /* A change event with HOTPLUG=1 is sent whenever a connector
+                 * changed state. Refresh the device to update our state. */
+                p = udev_device_get_property_value(ud, "HOTPLUG");
+                if (streq_ptr(p, "1"))
+                        grdrm_card_hotplug(card);
+        }
+}
diff --git a/src/libsystemd-terminal/grdev-internal.h b/src/libsystemd-terminal/grdev-internal.h
index 0064f0be02..96830a714c 100644
--- a/src/libsystemd-terminal/grdev-internal.h
+++ b/src/libsystemd-terminal/grdev-internal.h
@@ -47,6 +47,7 @@ typedef struct grdev_card               grdev_card;
 bool grdev_is_drm_card(grdev_card *card);
 grdev_card *grdev_find_drm_card(grdev_session *session, dev_t devnum);
 int grdev_drm_card_new(grdev_card **out, grdev_session *session, struct udev_device *ud);
+void grdev_drm_card_hotplug(grdev_card *card, struct udev_device *ud);
 
 /*
  * Displays
diff --git a/src/libsystemd-terminal/grdev.c b/src/libsystemd-terminal/grdev.c
index bb89ee7170..3e3833fc95 100644
--- a/src/libsystemd-terminal/grdev.c
+++ b/src/libsystemd-terminal/grdev.c
@@ -1150,7 +1150,7 @@ void grdev_session_hotplug_drm(grdev_session *session, struct udev_device *ud) {
         if (!card)
                 return;
 
-        /* TODO: hotplug card */
+        grdev_drm_card_hotplug(card, ud);
 }
 
 static void session_configure(grdev_session *session) {