[Intel-gfx] [PATCH] Revert "sna: Refresh last detection timestamp on hotplug notifies"

[Lyude]

From: Lyude Paul <cpaul at redhat.com>

DRM does not always update the status of each connector during a
hotplug event, and it's generally expected that userspace is supposed to
handle that by reprobing. This happens in a couple situations:
suspend/resume, MST hotplugs, and probably a few others. As a result,
making this assumption actually breaks MST hotplugging.

Signed-off-by: Lyude <cpaul at redhat.com>
---
 src/sna/sna_display.c | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/src/sna/sna_display.c b/src/sna/sna_display.c
index 16d0321..6299d1e 100644
--- a/src/sna/sna_display.c
+++ b/src/sna/sna_display.c
@@ -5038,14 +5038,11 @@ output_check_status(struct sna *sna, struct sna_output *output)
 	switch (compat_conn.conn.connection) {
 	case DRM_MODE_CONNECTED:
 		status = XF86OutputStatusConnected;
-		break;
 	case DRM_MODE_DISCONNECTED:
 		status = XF86OutputStatusDisconnected;
-		break;
 	default:
 	case DRM_MODE_UNKNOWNCONNECTION:
 		status = XF86OutputStatusUnknown;
-		break;
 	}
 	return output->status == status;
 }
@@ -5055,7 +5052,7 @@ void sna_mode_discover(struct sna *sna, bool tell)
 	ScreenPtr screen = xf86ScrnToScreen(sna->scrn);
 	xf86CrtcConfigPtr config = XF86_CRTC_CONFIG_PTR(sna->scrn);
 	struct drm_mode_card_res res;
-	uint32_t connectors[32], now;
+	uint32_t connectors[32];
 	unsigned changed = 0;
 	unsigned serial;
 	int i, j;
@@ -5087,7 +5084,6 @@ void sna_mode_discover(struct sna *sna, bool tell)
 	if (serial == 0)
 		serial = ++sna->mode.serial;
 
-	now = GetTimeInMillis();
 	for (i = 0; i < res.count_connectors; i++) {
 		DBG(("%s: connector[%d] = %d\n", __FUNCTION__, i, connectors[i]));
 		for (j = 0; j < sna->mode.num_real_output; j++) {
@@ -5113,13 +5109,10 @@ void sna_mode_discover(struct sna *sna, bool tell)
 			continue;
 
 		if (sna_output->serial == serial) {
-			if (output_check_status(sna, sna_output)) {
-				DBG(("%s: output %s (id=%d), retained state\n",
-				     __FUNCTION__, output->name, sna_output->id));
-				sna_output->last_detect = now;
-			} else {
-				DBG(("%s: output %s (id=%d), changed state, reprobing\n",
-				     __FUNCTION__, output->name, sna_output->id));
+			if (!output_check_status(sna, sna_output)) {
+				DBG(("%s: output %s (id=%d), changed state, reprobing]\n",
+				     __FUNCTION__, output->name, sna_output->id,
+				     sna_output->serial, serial));
 				sna_output->last_detect = 0;
 				changed |= 4;
 			}
-- 
2.5.5