From 582e70b0d3a412d15389a3c9c07a44791b311715 Mon Sep 17 00:00:00 2001
From: Gil Fine <gil.fine@linux.intel.com>
Date: Mon, 31 Jul 2023 05:25:40 +0300
Subject: thunderbolt: Change bandwidth reservations to comply USB4 v2
USB4 v2 Connection Manager guide (section 6.1.2.3) suggests to reserve
bandwidth in a sligthly different manner. It suggests to keep minimum of
1500 Mb/s for each path that carry a bulk traffic. Here we change the
bandwidth reservations to comply to the above for USB 3.x and PCIe
protocols over Gen 4 link, taking weights into account (that's 1500 Mb/s
for PCIe and 3000 Mb/s for USB 3.x).
For Gen 3 and below we use the existing reservation.
Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
drivers/thunderbolt/tb.c | 11 +++++++++++
1 file changed, 11 insertions(+)
(limited to 'drivers/thunderbolt/tb.c')
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 983b58d66096..1b379e9487b9 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -602,6 +602,7 @@ static int tb_available_bandwidth(struct tb *tb, struct tb_port *src_port,
/* Find the minimum available bandwidth over all links */
tb_for_each_port_on_path(src_port, dst_port, port) {
int link_speed, link_width, up_bw, down_bw;
+ int pci_reserved_up, pci_reserved_down;
if (!tb_port_is_null(port))
continue;
@@ -695,6 +696,16 @@ static int tb_available_bandwidth(struct tb *tb, struct tb_port *src_port,
up_bw -= usb3_consumed_up;
down_bw -= usb3_consumed_down;
+ /*
+ * If there is anything reserved for PCIe bulk traffic
+ * take it into account here too.
+ */
+ if (tb_tunnel_reserved_pci(port, &pci_reserved_up,
+ &pci_reserved_down)) {
+ up_bw -= pci_reserved_up;
+ down_bw -= pci_reserved_down;
+ }
+
if (up_bw < *available_up)
*available_up = up_bw;
if (down_bw < *available_down)
--
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