usb: typec: class: fix typec_altmode_put_partner to put plugs

commit 5962ded777d689cd8bf04454273e32228d7fb71f upstream.

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 is a plug evaluates
against the released altmode's partner instead of the calling altmode, so
change adev in typec_altmode_put_partner to properly refer to the altmode
being released.

Because typec_altmode_set_partner calls get_device() on the port altmode,
add partner_adev that points to the port altmode in typec_put_partner to
call put_device() on. typec_altmode_set_partner is not called for port
altmodes, so 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@vger.kernel.org>
Co-developed-by: Christian A. Ehrhardt <lk@c--e.de>
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Signed-off-by: RD Babiera <rdbabiera@google.com>
Tested-by: Christian A. Ehrhardt <lk@c--e.de>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240103181754.2492492-2-rdbabiera@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index 9c1dbf3..41382b1 100644 (file)
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -262,11 +262,13 @@ static void typec_altmode_put_partner(struct altmode *altmode)
 {
        struct altmode *partner = altmode->partner;
        struct typec_altmode *adev;
+       struct typec_altmode *partner_adev;
 
        if (!partner)
                return;
 
-       adev = &partner->adev;
+       adev = &altmode->adev;
+       partner_adev = &partner->adev;
 
        if (is_typec_plug(adev->dev.parent)) {
                struct typec_plug *plug = to_typec_plug(adev->dev.parent);
@@ -275,7 +277,7 @@ static void typec_altmode_put_partner(struct altmode *altmode)
        } else {
                partner->partner = NULL;
        }
-       put_device(&adev->dev);
+       put_device(&partner_adev->dev);
 }
 
 /**
@@ -496,7 +498,8 @@ 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);