From: Mario Limonciello mario.limonciello@amd.com
commit 31f87f705b3c1635345d8e8a493697099b43e508 upstream.
If any software has interacted with the USB4 registers before the Linux USB4 CM runs, it may have modified the plug events delay. It has been observed that if this value too large, it's possible that hotplugged devices will negotiate a fallback mode instead in Linux.
To prevent this, explicitly align the plug events delay with the USB4 spec value of 10ms.
Cc: stable@vger.kernel.org Signed-off-by: Mario Limonciello mario.limonciello@amd.com Signed-off-by: Mika Westerberg mika.westerberg@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/thunderbolt/switch.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -2046,6 +2046,7 @@ int tb_switch_configure(struct tb_switch * additional capabilities. */ sw->config.cmuv = USB4_VERSION_1_0; + sw->config.plug_events_delay = 0xa;
/* Enumerate the switch */ ret = tb_sw_write(sw, (u32 *)&sw->config + 1, TB_CFG_SWITCH,