[PATCH] usb: typec: mux: fsa4480: Keep the USB 2.0 switch on in DP-only modes

[PATCH] usb: typec: mux: fsa4480: Keep the USB 2.0 switch on in DP-only modes

[Joonhoe Kim]

DisplayPort pin assignments C and E give all four SuperSpeed lanes to
DisplayPort, but the USB 2.0 D+/D- pair is not part of the pin
assignment and stays available. The FSA4480 sits on that pair, and in
these modes the driver turns its USB switch off, so a USB 2.0 hub or
device behind a DisplayPort sink is disconnected as soon as the
DisplayPort mode is set.

Configure the USB switch the same way in all DisplayPort modes.

Fixes: c7054c31c1c9 ("usb: typec: fsa4480: rework mux & switch setup to handle more states")
Signed-off-by: Joonhoe Kim <26rote@gmail.com>
---
Tested on a Lenovo Y700 Gen 5 (TB323FU, Kaanapali; out-of-tree board
support) with a USB-C monitor in pin assignment C: its USB 2.0 hub was
disconnected when the mux was set; with this change the hub and the
keyboard behind it stay connected.

 drivers/usb/typec/mux/fsa4480.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/usb/typec/mux/fsa4480.c b/drivers/usb/typec/mux/fsa4480.c
index bea0c1deec94..e05ab3c10c81 100644
--- a/drivers/usb/typec/mux/fsa4480.c
+++ b/drivers/usb/typec/mux/fsa4480.c
@@ -93,16 +93,9 @@ static int fsa4480_set(struct fsa4480 *fsa)
 		sel = FSA4480_SEL_USB;
 	} else if (fsa->svid) {
 		switch (fsa->mode) {
-		/* DP Only */
 		case TYPEC_DP_STATE_C:
-		case TYPEC_DP_STATE_E:
-			enable |= FSA4480_ENABLE_SBU;
-			if (reverse)
-				sel = FSA4480_SEL_SBU_REVERSE;
-			break;
-
-		/* DP + USB */
 		case TYPEC_DP_STATE_D:
+		case TYPEC_DP_STATE_E:
 		case TYPEC_DP_STATE_F:
 			enable |= FSA4480_ENABLE_USB | FSA4480_ENABLE_SBU;
 			sel = FSA4480_SEL_USB;

base-commit: 2efb7a11f1aa4d2dc285fe2680cca22cb9f72f64
-- 
2.43.0