FAILED: patch "[PATCH] usb: typec: altmodes/displayport: create sysfs nodes as" failed to apply to 4.19-stable tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

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@xxxxxxxxxxxxxxx>.

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 165376f6b23e9a779850e750fb2eb06622e5a531
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2024032707-fang-recede-3104@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

165376f6b23e ("usb: typec: altmodes/displayport: create sysfs nodes as driver's default device attribute group")
001b0c780eac ("usb: typec: altmodes/displayport: Add hpd sysfs attribute")
7f8113948785 ("usb: typec: altmodes/displayport: Notify drm subsys of hotplug events")
318ebed29718 ("usb: typec: altmodes: displayport: Supply missing displayport.h include file")

thanks,

greg k-h

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

>From 165376f6b23e9a779850e750fb2eb06622e5a531 Mon Sep 17 00:00:00 2001
From: RD Babiera <rdbabiera@xxxxxxxxxx>
Date: Thu, 29 Feb 2024 00:11:02 +0000
Subject: [PATCH] usb: typec: altmodes/displayport: create sysfs nodes as
 driver's default device attribute group

The DisplayPort driver's sysfs nodes may be present to the userspace before
typec_altmode_set_drvdata() completes in dp_altmode_probe. This means that
a sysfs read can trigger a NULL pointer error by deferencing dp->hpd in
hpd_show or dp->lock in pin_assignment_show, as dev_get_drvdata() returns
NULL in those cases.

Remove manual sysfs node creation in favor of adding attribute group as
default for devices bound to the driver. The ATTRIBUTE_GROUPS() macro is
not used here otherwise the path to the sysfs nodes is no longer compliant
with the ABI.

Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: RD Babiera <rdbabiera@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240229001101.3889432-2-rdbabiera@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index f81bec0c7b86..f8ea3054be54 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -559,16 +559,21 @@ static ssize_t hpd_show(struct device *dev, struct device_attribute *attr, char
 }
 static DEVICE_ATTR_RO(hpd);
 
-static struct attribute *dp_altmode_attrs[] = {
+static struct attribute *displayport_attrs[] = {
 	&dev_attr_configuration.attr,
 	&dev_attr_pin_assignment.attr,
 	&dev_attr_hpd.attr,
 	NULL
 };
 
-static const struct attribute_group dp_altmode_group = {
+static const struct attribute_group displayport_group = {
 	.name = "displayport",
-	.attrs = dp_altmode_attrs,
+	.attrs = displayport_attrs,
+};
+
+static const struct attribute_group *displayport_groups[] = {
+	&displayport_group,
+	NULL,
 };
 
 int dp_altmode_probe(struct typec_altmode *alt)
@@ -576,7 +581,6 @@ int dp_altmode_probe(struct typec_altmode *alt)
 	const struct typec_altmode *port = typec_altmode_get_partner(alt);
 	struct fwnode_handle *fwnode;
 	struct dp_altmode *dp;
-	int ret;
 
 	/* FIXME: Port can only be DFP_U. */
 
@@ -587,10 +591,6 @@ int dp_altmode_probe(struct typec_altmode *alt)
 	      DP_CAP_PIN_ASSIGN_DFP_D(alt->vdo)))
 		return -ENODEV;
 
-	ret = sysfs_create_group(&alt->dev.kobj, &dp_altmode_group);
-	if (ret)
-		return ret;
-
 	dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL);
 	if (!dp)
 		return -ENOMEM;
@@ -624,7 +624,6 @@ void dp_altmode_remove(struct typec_altmode *alt)
 {
 	struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
 
-	sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group);
 	cancel_work_sync(&dp->work);
 
 	if (dp->connector_fwnode) {
@@ -649,6 +648,7 @@ static struct typec_altmode_driver dp_altmode_driver = {
 	.driver = {
 		.name = "typec_displayport",
 		.owner = THIS_MODULE,
+		.dev_groups = displayport_groups,
 	},
 };
 module_typec_altmode_driver(dp_altmode_driver);