From 6cb27a04fb779717c4a3d20233b93596885838cf Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Thu, 18 Nov 2021 09:06:45 +0200 Subject: thunderbolt: Do not allow subtracting more NFC credits than configured This might happen if the boot firmware uses different amount of NFC credits than what the router suggests, or we are dealing with pre-USB4 device. Signed-off-by: Mika Westerberg --- drivers/thunderbolt/switch.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/thunderbolt') diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c index 3014146081c1..463cfdc0b42f 100644 --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -623,6 +623,9 @@ int tb_port_add_nfc_credits(struct tb_port *port, int credits) return 0; nfc_credits = port->config.nfc_credits & ADP_CS_4_NFC_BUFFERS_MASK; + if (credits < 0) + credits = max_t(int, -nfc_credits, credits); + nfc_credits += credits; tb_port_dbg(port, "adding %d NFC credits to %lu", credits, -- cgit v1.2.3