FAILED: patch "[PATCH] usb: typec: altmodes/displayport: Signal hpd low when exiting" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 89434b069e460967624903b049e5cf5c9e6b99b9
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023101554-trance-enduring-ffc6@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 89434b069e460967624903b049e5cf5c9e6b99b9 Mon Sep 17 00:00:00 2001
From: RD Babiera <[email protected]>
Date: Mon, 9 Oct 2023 21:00:58 +0000
Subject: [PATCH] usb: typec: altmodes/displayport: Signal hpd low when exiting
mode

Upon receiving an ACK for a sent EXIT_MODE message, the DisplayPort driver currently resets the status and configuration of the port partner. The hpd signal is not updated despite being part of the status, so the Display stack can still transmit video despite typec_altmode_exit placing the lanes in a Safe State.

Set hpd to low when a sent EXIT_MODE message is ACK'ed.

index 426c88a516e5..59e0218a8bc5 100644
@@ -304,6 +304,11 @@ static int dp_altmode_vdm(struct typec_altmode *alt,
 			typec_altmode_update_active(alt, false);
 			dp->data.status = 0;
 			dp->data.conf = 0;
+			if (dp->hpd) {
+				drm_connector_oob_hotplug_event(dp->connector_fwnode);
+				dp->hpd = false;
+				sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
+			}
 			break;
 		case DP_CMD_STATUS_UPDATE:
 			dp->data.status = *vdo;