When tunneling aggregated USB3 (20 Gb/s) the bandwidth values that are
programmed to the ADP_USB3_CS_2 go higher than 4096 and that does not
fit anymmore to the 12-bit field. Fix this by scaling the value using
the scale field accordingly.
Fixes: 3b1d8d577ca8 ("thunderbolt: Implement USB3 bandwidth negotiation routines")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
drivers/thunderbolt/usb4.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 6e87cf993c68..a0996cb2893c 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -2094,18 +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)
--
2.39.1
