modesetting: check the kms state on EnterVT

Normally, we would receive a uevent coming from Linux's DRM subsystem,
which would trigger the check for disappearing/appearing resources.
However, this event is not received when X is not master (another VT
is selected), and so the userspace / desktop environment would not be
notified about the changes that happened while X wasn't master.

To fix the issue, this patch forces a refresh on EnterVT by splitting
the kms-checking code from the uevent handling into its own (exported)
function called drmmode_update_kms_state. This function is then called
from both the uevent-handling function, and on EnterVT right before
restoring the modes.

Signed-off-by: Martin Peres <martin.peres@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Kishore Kadiyala <kishore.kadiyala@intel.com>
Tested-by: Kishore Kadiyala <kishore.kadiyala@intel.com>

hw/xfree86/drivers/modesetting/driver.c

@@ -2014,6 +2014,8 @@ EnterVT(ScrnInfoPtr pScrn)
 
     SetMaster(pScrn);
 
+    drmmode_update_kms_state(&ms->drmmode);
+
     if (!drmmode_set_desired_modes(pScrn, &ms->drmmode, TRUE))
         return FALSE;
 

hw/xfree86/drivers/modesetting/drmmode_display.c

@@ -3721,30 +3721,19 @@ drmmode_setup_colormap(ScreenPtr pScreen, ScrnInfoPtr pScrn)
     return TRUE;
 }
 
-#ifdef CONFIG_UDEV_KMS
-
 #define DRM_MODE_LINK_STATUS_GOOD       0
 #define DRM_MODE_LINK_STATUS_BAD        1
 
-static void
+void
-drmmode_handle_uevents(int fd, void *closure)
+drmmode_update_kms_state(drmmode_ptr drmmode)
 {
-    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 = FALSE;
     Bool changed = FALSE;
 
-    while ((dev = udev_monitor_receive_device(drmmode->uevent_monitor))) {
-        udev_device_unref(dev);
-        found = TRUE;
-    }
-    if (!found)
-        return;
-
     /* Try to re-set the mode on all the connectors with a BAD link-state:
      * This may happen if a link degrades and a new modeset is necessary, using
      * different link-training parameters. If the kernel found that the current
@@ -3859,6 +3848,25 @@ out:
 #undef DRM_MODE_LINK_STATUS_BAD
 #undef DRM_MODE_LINK_STATUS_GOOD
 
+#ifdef CONFIG_UDEV_KMS
+
+static void
+drmmode_handle_uevents(int fd, void *closure)
+{
+    drmmode_ptr drmmode = closure;
+    struct udev_device *dev;
+    Bool found = FALSE;
+
+    while ((dev = udev_monitor_receive_device(drmmode->uevent_monitor))) {
+        udev_device_unref(dev);
+        found = TRUE;
+    }
+    if (!found)
+        return;
+
+    drmmode_update_kms_state(drmmode);
+}
+
 #endif
 
 void

hw/xfree86/drivers/modesetting/drmmode_display.h

@@ -283,6 +283,7 @@ void drmmode_adjust_frame(ScrnInfoPtr pScrn, drmmode_ptr drmmode, int x, int y);
 extern Bool drmmode_set_desired_modes(ScrnInfoPtr pScrn, drmmode_ptr drmmode, Bool set_hw);
 extern Bool drmmode_setup_colormap(ScreenPtr pScreen, ScrnInfoPtr pScrn);
 
+extern void drmmode_update_kms_state(drmmode_ptr drmmode);
 extern void drmmode_uevent_init(ScrnInfoPtr scrn, drmmode_ptr drmmode);
 extern void drmmode_uevent_fini(ScrnInfoPtr scrn, drmmode_ptr drmmode);