[PATCH v2 6/6] usb: typec: tcpm: Add WARN_ON ensure we are not trying to send 2 VDM packets at the same time

[Hans de Goede <hdegoede@redhat.com>]

The tcpm.c code for sending VDMs assumes that there will only be one VDM
in flight at the time. The "queue" used by tcpm_queue_vdm is only 1 entry
deep.

This assumes that the higher layers (tcpm state-machine and alt-mode
drivers) ensure that queuing a new VDM before the old one has been
completely send (or it timed out) add a WARN_ON to check for this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
- Fix typo in commit-msg subject
---
 drivers/usb/typec/tcpm/tcpm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 9b26b57a0172..cc786d558f14 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -971,6 +971,9 @@ static void tcpm_queue_vdm(struct tcpm_port *port, const u32 header,
 {
 	WARN_ON(!mutex_is_locked(&port->lock));
 
+	/* Make sure we are not still processing a previous VDM packet */
+	WARN_ON(port->vdm_state > VDM_STATE_DONE);
+
 	port->vdo_count = cnt + 1;
 	port->vdo_data[0] = header;
 	memcpy(&port->vdo_data[1], data, sizeof(u32) * cnt);
-- 
2.26.2