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authorMika Westerberg <mika.westerberg@linux.intel.com>2021-11-18 09:06:45 +0200
committerMika Westerberg <mika.westerberg@linux.intel.com>2021-12-07 15:18:33 +0300
commit6cb27a04fb779717c4a3d20233b93596885838cf (patch)
treee8394e37239e678d31d726aebd2860d39019f2ac /drivers/thunderbolt
parent1e56c88adecc2dfe14973fa47898861a839e62d4 (diff)
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 <mika.westerberg@linux.intel.com>
Diffstat (limited to 'drivers/thunderbolt')
-rw-r--r--drivers/thunderbolt/switch.c3
1 files changed, 3 insertions, 0 deletions
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,