usb: typec: ucsi: Fix a deadlock in ucsi_send_command_common()

The function returns with the ppm_lock held if the PPM is
busy or there's an error.

Reported-and-tested-by: Luciano Coelho <luciano.coelho@intel.com>
Fixes: 5e9c1662a89b ("usb: typec: ucsi: rework command execution functions")
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reported-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20240806112029.2984319-1-heikki.krogerus@linux.intel.com
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 dcd3765cc1f532242af91ad1af5389b63adb87f0..432a2d6266d714591ea1c5c5d6b51a0eacd74fa3 100644 (file)
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -238,13 +238,10 @@ static int ucsi_send_command_common(struct ucsi *ucsi, u64 cmd,
        mutex_lock(&ucsi->ppm_lock);
 
        ret = ucsi_run_command(ucsi, cmd, &cci, data, size, conn_ack);
-       if (cci & UCSI_CCI_BUSY) {
-               ret = ucsi_run_command(ucsi, UCSI_CANCEL, &cci, NULL, 0, false);
-               return ret ? ret : -EBUSY;
-       }
-
-       if (cci & UCSI_CCI_ERROR)
-               return ucsi_read_error(ucsi, connector_num);
+       if (cci & UCSI_CCI_BUSY)
+               ret = ucsi_run_command(ucsi, UCSI_CANCEL, &cci, NULL, 0, false) ?: -EBUSY;
+       else if (cci & UCSI_CCI_ERROR)
+               ret = ucsi_read_error(ucsi, connector_num);
 
        mutex_unlock(&ucsi->ppm_lock);
        return ret;