This is a note to let you know that I've just added the patch titled
thunderbolt: Use scale field when allocating USB3 bandwidth
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
thunderbolt-use-scale-field-when-allocating-usb3-bandwidth.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c82510b1d87bdebfe916048857d2ef46f1778aa5 Mon Sep 17 00:00:00 2001
From: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Date: Tue, 27 Dec 2022 11:55:26 +0200
Subject: thunderbolt: Use scale field when allocating USB3 bandwidth
From: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
commit c82510b1d87bdebfe916048857d2ef46f1778aa5 upstream.
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 anymore 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/thunderbolt/usb4.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -1636,18 +1636,30 @@ static int usb4_usb3_port_write_allocate
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)
Patches currently in stable-queue which might be from mika.westerberg@xxxxxxxxxxxxxxx are
queue-5.10/thunderbolt-use-const-qualifier-for-ring_interrupt_index.patch
queue-5.10/thunderbolt-use-scale-field-when-allocating-usb3-bandwidth.patch
