[PATCH 4/6] thunderbolt: Do not allow subtracting more NFC credits than configured
From: Mika Westerberg <mika.westerberg@linux.intel.com>
Date: 2021-11-25 07:45:46
Subsystem:
the rest, thunderbolt driver · Maintainers:
Linus Torvalds, Andreas Noever, Mika Westerberg, Yehezkel Bernat
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 <mika.westerberg@linux.intel.com> --- drivers/thunderbolt/switch.c | 3 +++ 1 file changed, 3 insertions(+)
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,
--
2.33.0