1 files changed, 46 insertions, 7 deletions

diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 1e5e9c147a31..a0996cb2893c 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -1579,6 +1579,20 @@ int usb4_port_retimer_set_inbound_sbtx(struct tb_port *port, u8 index)
 }
 
 /**
+ * usb4_port_retimer_unset_inbound_sbtx() - Disable sideband channel transactions
+ * @port: USB4 port
+ * @index: Retimer index
+ *
+ * Disables sideband channel transations on SBTX. The reverse of
+ * usb4_port_retimer_set_inbound_sbtx().
+ */
+int usb4_port_retimer_unset_inbound_sbtx(struct tb_port *port, u8 index)
+{
+	return usb4_port_retimer_op(port, index,
+				    USB4_SB_OPCODE_UNSET_INBOUND_SBTX, 500);
+}
+
+/**
  * usb4_port_retimer_read() - Read from retimer sideband registers
  * @port: USB4 port
  * @index: Retimer index
@@ -1868,6 +1882,15 @@ int usb4_port_retimer_nvm_read(struct tb_port *port, u8 index,
 				usb4_port_retimer_nvm_read_block, &info);
 }
 
+static inline unsigned int
+usb4_usb3_port_max_bandwidth(const struct tb_port *port, unsigned int bw)
+{
+	/* Take the possible bandwidth limitation into account */
+	if (port->max_bw)
+		return min(bw, port->max_bw);
+	return bw;
+}
+
 /**
  * usb4_usb3_port_max_link_rate() - Maximum support USB3 link rate
  * @port: USB3 adapter port
@@ -1889,7 +1912,9 @@ int usb4_usb3_port_max_link_rate(struct tb_port *port)
 		return ret;
 
 	lr = (val & ADP_USB3_CS_4_MSLR_MASK) >> ADP_USB3_CS_4_MSLR_SHIFT;
-	return lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
+	ret = lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
+
+	return usb4_usb3_port_max_bandwidth(port, ret);
 }
 
 /**
@@ -1916,7 +1941,9 @@ int usb4_usb3_port_actual_link_rate(struct tb_port *port)
 		return 0;
 
 	lr = val & ADP_USB3_CS_4_ALR_MASK;
-	return lr == ADP_USB3_CS_4_ALR_20G ? 20000 : 10000;
+	ret = lr == ADP_USB3_CS_4_ALR_20G ? 20000 : 10000;
+
+	return usb4_usb3_port_max_bandwidth(port, ret);
 }
 
 static int usb4_usb3_port_cm_request(struct tb_port *port, bool request)
@@ -2067,18 +2094,30 @@ static int usb4_usb3_port_write_allocated_bandwidth(struct tb_port *port,
 						    int downstream_bw)
 {
 	u32 val, ubw, dbw, scale;
-	int ret;
+	int ret, max_bw;
 
-	/* Read the used scale, hardware default is 0 */
-	ret = tb_port_read(port, &scale, TB_CFG_PORT,
-			   port->cap_adap + ADP_USB3_CS_3, 1);
+	/* Figure out suitable scale */
+	scale = 0;
+	max_bw = max(upstream_bw, downstream_bw);
+	while (scale < 64) {
+		if (mbps_to_usb3_bw(max_bw, scale) < 4096)
+			break;
+		scale++;
+	}
+
+	if (WARN_ON(scale >= 64))
+		return -EINVAL;
+
+	ret = tb_port_write(port, &scale, TB_CFG_PORT,
+			    port->cap_adap + ADP_USB3_CS_3, 1);
 	if (ret)
 		return ret;
 
-	scale &= ADP_USB3_CS_3_SCALE_MASK;
 	ubw = mbps_to_usb3_bw(upstream_bw, scale);
 	dbw = mbps_to_usb3_bw(downstream_bw, scale);
 
+	tb_port_dbg(port, "scaled bandwidth %u/%u, scale %u\n", ubw, dbw, scale);
+
 	ret = tb_port_read(port, &val, TB_CFG_PORT,
 			   port->cap_adap + ADP_USB3_CS_2, 1);
 	if (ret)