Rick reported that his Pluggable USB4 dock does not work anymore after
upgrading to v6.10 kernel.
It looks like commit c6ca1ac9f472 ("thunderbolt: Increase sideband
access polling delay") makes the device router enumeration happen later
than what might be expected by the dock (although there is no such limit
in the USB4 spec) which probably makes it assume there is something
wrong with the high-speed link and reset it. After the link is reset the
same issue happens again and again.
For this reason lower the sideband access delay from 5ms to 1ms. This
seems to work fine according to Rick's testing.
Reported-by: Rick Lahaye <rick@xxxxxxxxxx>
Closes: https://lore.kernel.org/linux-usb/000f01db247b$d10e1520$732a3f60$@581238.xyz/
Tested-by: Rick Lahaye <rick@xxxxxxxxxx>
Fixes: c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
v1: https://lore.kernel.org/linux-usb/20241105085301.524312-1-mika.westerberg@xxxxxxxxxxxxxxx/
Changes from v1:
* Reword the commit message to use mainline kernel version (v6.10)
instead.
drivers/thunderbolt/usb4.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 0a9b4aeb3fa1..402fdf8b1cde 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -48,7 +48,7 @@ enum usb4_ba_index {
/* Delays in us used with usb4_port_wait_for_bit() */
#define USB4_PORT_DELAY 50
-#define USB4_PORT_SB_DELAY 5000
+#define USB4_PORT_SB_DELAY 1000
static int usb4_native_switch_op(struct tb_switch *sw, u16 opcode,
u32 *metadata, u8 *status,
--
2.45.2
