[PATCH v3 2/2] platform/chrome: cros_ec_typec: Reorder altmode registration

[Andrei Kuchynski <akuchynski@chromium.org>]

By default, alternate mode priorities are set in registration order, with
the last mode registered taking precedence. Changing the registration order
of alternate modes prioritizes DisplayPort over Thunderbolt.

Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
---
 drivers/platform/chrome/cros_ec_typec.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 89d29ef040879..11d9589422eeb 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -406,16 +406,10 @@ static int cros_typec_register_port_altmodes(struct cros_typec_data *typec,
 	struct typec_altmode_desc desc;
 	struct typec_altmode *amode;
 
-	/* All PD capable CrOS devices are assumed to support DP altmode. */
-	memset(&desc, 0, sizeof(desc));
-	desc.svid = USB_TYPEC_DP_SID;
-	desc.mode = USB_TYPEC_DP_MODE;
-	desc.vdo = DP_PORT_VDO;
-	amode = cros_typec_register_displayport(port, &desc,
-						typec->ap_driven_altmode);
-	if (IS_ERR(amode))
-		return PTR_ERR(amode);
-	port->port_altmode[CROS_EC_ALTMODE_DP] = amode;
+	/*
+	 * Alternate modes registered later take precedence. Register DisplayPort
+	 * after Thunderbolt to prioritize DisplayPort over Thunderbolt.
+	 */
 
 	/*
 	 * Register TBT compatibility alt mode. The EC will not enter the mode
@@ -433,6 +427,17 @@ static int cros_typec_register_port_altmodes(struct cros_typec_data *typec,
 		port->port_altmode[CROS_EC_ALTMODE_TBT] = amode;
 	}
 
+	/* All PD capable CrOS devices are assumed to support DP altmode. */
+	memset(&desc, 0, sizeof(desc));
+	desc.svid = USB_TYPEC_DP_SID;
+	desc.mode = USB_TYPEC_DP_MODE;
+	desc.vdo = DP_PORT_VDO;
+	amode = cros_typec_register_displayport(port, &desc,
+						typec->ap_driven_altmode);
+	if (IS_ERR(amode))
+		return PTR_ERR(amode);
+	port->port_altmode[CROS_EC_ALTMODE_DP] = amode;
+
 	port->state.alt = NULL;
 	port->state.mode = TYPEC_STATE_USB;
 	port->state.data = NULL;
-- 
2.56.0.385.gac671c819a-goog