thunderbolt: Fix connection issue with Pluggable UD-4VPD dock

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@581238.xyz>
Closes: https://lore.kernel.org/linux-usb/000f01db247b$d10e1520$732a3f60$@581238.xyz/
Tested-by: Rick Lahaye <rick@581238.xyz>
Fixes: c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay")
Cc: stable@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 0a9b4aeb3fa140f2bcfdbb03a4e27426e6c7f8f2..402fdf8b1cdecaa49bcc39449437e588a0ddd5b4 100644 (file)
--- 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,