[PATCH v3] usb: typec: class: fix typec_altmode_put_partner to put plugs

[RD Babiera]

When typec_altmode_put_partner is called by a plug altmode upon release,
the port altmode the plug belongs to will not remove its reference to the
plug. The check to see if the altmode being released evaluates against the
released altmode's partner instead of the calling altmode itself, so change
adev in typec_altmode_put_partner to properly refer to the altmode being
released.

typec_altmode_set_partner is not run for port altmodes, so also add a check
in typec_altmode_release to prevent typec_altmode_put_partner() calls on
port altmode release.

Fixes: 8a37d87d72f0 ("usb: typec: Bus type for alternate modes")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: RD Babiera <rdbabiera@xxxxxxxxxx>
---
Changes since v2:
* Moved changelog under "Signed-off-by" tag

Changes since v1:
* Changed commit message for clarity
* Added check to typec_altmode_release to only call put_partner if altmode
belongs to port partner or plug
---
 drivers/usb/typec/class.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index 2e0451bd336e..16a670828dde 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -267,7 +267,7 @@ static void typec_altmode_put_partner(struct altmode *altmode)
 	if (!partner)
 		return;
 
-	adev = &partner->adev;
+	adev = &altmode->adev;
 
 	if (is_typec_plug(adev->dev.parent)) {
 		struct typec_plug *plug = to_typec_plug(adev->dev.parent);
@@ -497,7 +497,8 @@ static void typec_altmode_release(struct device *dev)
 {
 	struct altmode *alt = to_altmode(to_typec_altmode(dev));
 
-	typec_altmode_put_partner(alt);
+	if (!is_typec_port(dev->parent))
+		typec_altmode_put_partner(alt);
 
 	altmode_id_remove(alt->adev.dev.parent, alt->id);
 	kfree(alt);

base-commit: 24af68a0ed53629bdde7b53ef8c2be72580d293b
-- 
2.43.0.rc1.413.gea7ed67945-goog