[PATCH 6.1 048/197] usb: ucsi: Add missing ppm_lock

Greg Kroah-Hartman
2024-02-20T21:00:23Z

From: Christian A. Ehrhardt <lk@c--e.de>

commit c9aed03a0a683fd1600ea92f2ad32232d4736272 upstream.

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>
---
drivers/usb/typec/ucsi/ucsi.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -831,7 +831,9 @@ static void ucsi_handle_connector_change

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);