FAILED: patch "[PATCH] usb: typec: altmodes/displayport: Fix configure initial pin" failed to apply to 4.19-stable tree

FAILED: patch "[PATCH] usb: typec: altmodes/displayport: Fix configure initial pin" failed to apply to 4.19-stable tree

[gregkh]

The patch below does not apply to the 4.19-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 <stable@vger.kernel.org>.

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-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x eddebe39602efe631b83ff8d03f26eba12cfd760
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023041032-pasty-shifty-db8c@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

eddebe39602e ("usb: typec: altmodes/displayport: Fix configure initial pin assignment")
09fed4d64d3f ("usb: typec: altmodes/displayport: Fall back to multi-func pins")

thanks,

greg k-h

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

From eddebe39602efe631b83ff8d03f26eba12cfd760 Mon Sep 17 00:00:00 2001
From: RD Babiera <rdbabiera@google.com>
Date: Wed, 29 Mar 2023 21:51:59 +0000
Subject: [PATCH] usb: typec: altmodes/displayport: Fix configure initial pin
 assignment

While determining the initial pin assignment to be sent in the configure
message, using the DP_PIN_ASSIGN_DP_ONLY_MASK mask causes the DFP_U to
send both Pin Assignment C and E when both are supported by the DFP_U and
UFP_U. The spec (Table 5-7 DFP_U Pin Assignment Selection Mandates,
VESA DisplayPort Alt Mode Standard v2.0) indicates that the DFP_U never
selects Pin Assignment E when Pin Assignment C is offered.

Update the DP_PIN_ASSIGN_DP_ONLY_MASK conditional to intially select only
Pin Assignment C if it is available.

Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode")
Cc: stable@vger.kernel.org
Signed-off-by: RD Babiera <rdbabiera@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20230329215159.2046932-1-rdbabiera@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index 662cd043b50e..8f3e884222ad 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -112,8 +112,12 @@ static int dp_altmode_configure(struct dp_altmode *dp, u8 con)
 		if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC &&
 		    pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
 			pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK;
-		else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK)
+		else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK) {
 			pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK;
+			/* Default to pin assign C if available */
+			if (pin_assign & BIT(DP_PIN_ASSIGN_C))
+				pin_assign = BIT(DP_PIN_ASSIGN_C);
+		}
 
 		if (!pin_assign)
 			return -EINVAL;