From 81e759d71a6bff49a709b9c950887b8dda1541c6 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Wed, 21 Sep 2022 09:54:32 -0500 Subject: [PATCH] thunderbolt: Explicitly reset plug events delay back to USB4 spec value 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 Signed-off-by: Mika Westerberg Signed-off-by: Greg Kroah-Hartman --- drivers/thunderbolt/switch.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c index 3014146..50a5b16 100644 --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -2281,6 +2281,7 @@ int tb_switch_configure(struct tb_switch *sw) * 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, -- 2.7.4