phy: rockchip-typec: fix tcphy_get_mode error case

The existing logic in tcphy_get_mode() can cause the phy to be
incorrectly configured to USB UFP or DisplayPort mode when
extcon_get_state returns an error code.

extcon_get_state() can return 0, 1, or a negative error code.

It is possible to get into the failing state with an extcon driver
which does not support the extcon connector id specified as the
second argument to extcon_get_state().

tcphy_get_mode()
->extcon_get_state()
-->find_cable_index_by_id()
--->return -EINVAL;

Fixes: e96be45 ("phy: Add USB Type-C PHY driver for rk3399")
Signed-off-by: Neill Kapron <[email protected]>
Reviewed-by: Lee Jones <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>

Author: nkapron

drivers/phy/rockchip/phy-rockchip-typec.c

@@ -821,10 +821,10 @@ static int tcphy_get_mode(struct rockchip_typec_phy *tcphy)
 	mode = MODE_DFP_USB;
 	id = EXTCON_USB_HOST;
 
-	if (ufp) {
+	if (ufp > 0) {
 		mode = MODE_UFP_USB;
 		id = EXTCON_USB;
-	} else if (dp) {
+	} else if (dp > 0) {
 		mode = MODE_DFP_DP;
 		id = EXTCON_DISP_DP;