6.6-stable review patch. If anyone has any objections, please let me know.
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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 @@ -935,7 +935,9 @@ 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);