[PATCH 4/8] thunderbolt: Take CL states into account when waiting for link to come up

[Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>]

If CL states are enabled for the link it may be in these states too when
reading the lane adapter state but it will enter CL0 as soon as there is
traffic in the high-speed lanes. Upon discovery we want to make sure
that is accounted as the link being up, otherwise we end up tearing down
the topology with no good reason.

Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
 drivers/thunderbolt/switch.c  | 42 +++++++++++++++++++++--------------
 drivers/thunderbolt/tb_regs.h |  4 ++++
 2 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 363d712aa364..e1ad1b437291 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -513,36 +513,44 @@ int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
 
 	while (retries--) {
 		state = tb_port_state(port);
-		if (state < 0)
-			return state;
-		if (state == TB_PORT_DISABLED) {
+		switch (state) {
+		case TB_PORT_DISABLED:
 			tb_port_dbg(port, "is disabled (state: 0)\n");
 			return 0;
-		}
-		if (state == TB_PORT_UNPLUGGED) {
+
+		case TB_PORT_UNPLUGGED:
 			if (wait_if_unplugged) {
 				/* used during resume */
 				tb_port_dbg(port,
 					    "is unplugged (state: 7), retrying...\n");
 				msleep(100);
-				continue;
+				break;
 			}
 			tb_port_dbg(port, "is unplugged (state: 7)\n");
 			return 0;
-		}
-		if (state == TB_PORT_UP) {
-			tb_port_dbg(port, "is connected, link is up (state: 2)\n");
+
+		case TB_PORT_UP:
+		case TB_PORT_TX_CL0S:
+		case TB_PORT_RX_CL0S:
+		case TB_PORT_CL1:
+		case TB_PORT_CL2:
+			tb_port_dbg(port, "is connected, link is up (state: %d)\n", state);
 			return 1;
+
+		default:
+			if (state < 0)
+				return state;
+
+			/*
+			 * After plug-in the state is TB_PORT_CONNECTING. Give it some
+			 * time.
+			 */
+			tb_port_dbg(port,
+				    "is connected, link is not up (state: %d), retrying...\n",
+				    state);
+			msleep(100);
 		}
 
-		/*
-		 * After plug-in the state is TB_PORT_CONNECTING. Give it some
-		 * time.
-		 */
-		tb_port_dbg(port,
-			    "is connected, link is not up (state: %d), retrying...\n",
-			    state);
-		msleep(100);
 	}
 	tb_port_warn(port,
 		     "failed to reach state TB_PORT_UP. Ignoring port...\n");
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index 3c38b0cb8f74..f4a194cc0d63 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -50,6 +50,10 @@ enum tb_port_state {
 	TB_PORT_DISABLED	= 0, /* tb_cap_phy.disable == 1 */
 	TB_PORT_CONNECTING	= 1, /* retry */
 	TB_PORT_UP		= 2,
+	TB_PORT_TX_CL0S		= 3,
+	TB_PORT_RX_CL0S		= 4,
+	TB_PORT_CL1		= 5,
+	TB_PORT_CL2		= 6,
 	TB_PORT_UNPLUGGED	= 7,
 };
 
-- 
2.35.1