usb: ucsi: Add missing ppm_lock

Calling ->sync_write must be done while holding the PPM lock as
the mailbox logic does not support concurrent commands.

At least since the addition of partner task this means that
ucsi_acknowledge_connector_change should be called with the
PPM lock held as it calls ->sync_write.

Thus protect the only call to ucsi_acknowledge_connector_change
with the PPM. All other calls to ->sync_write already happen
under the PPM lock.

Fixes: b9aa02ca39a4 ("usb: typec: ucsi: Add polling mechanism for partner tasks like alt mode checking")
Cc: stable@vger.kernel.org
Signed-off-by: "Christian A. Ehrhardt" <lk@c--e.de>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240121204123.275441-2-lk@c--e.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 5392ec6989592041f87b96a7af1479621be799a0..14f5a7bfae2e92873e405b369ca8ce5620d856c0 100644 (file)
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -938,7 +938,9 @@ static void ucsi_handle_connector_change(struct work_struct *work)
 
        clear_bit(EVENT_PENDING, &con->ucsi->flags);
 
+       mutex_lock(&ucsi->ppm_lock);
        ret = ucsi_acknowledge_connector_change(ucsi);
+       mutex_unlock(&ucsi->ppm_lock);
        if (ret)
                dev_err(ucsi->dev, "%s: ACK failed (%d)", __func__, ret);