linux: update b53 upstream driver

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

1 files changed, 39 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.10/792-v5.15-0001-net-dsa-b53-Fix-calculating-number-of-switch-ports.patch b/target/linux/generic/backport-5.10/792-v5.15-0001-net-dsa-b53-Fix-calculating-number-of-switch-ports.patch
new file mode 100644
index 0000000000..4a7cbd9a4f
--- /dev/null
+++ b/target/linux/generic/backport-5.10/792-v5.15-0001-net-dsa-b53-Fix-calculating-number-of-switch-ports.patch
@@ -0,0 +1,39 @@
+From cdb067d31c0fe4cce98b9d15f1f2ef525acaa094 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Thu, 2 Sep 2021 10:30:50 +0200
+Subject: [PATCH] net: dsa: b53: Fix calculating number of switch ports
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+It isn't true that CPU port is always the last one. Switches BCM5301x
+have 9 ports (port 6 being inactive) and they use port 5 as CPU by
+default (depending on design some other may be CPU ports too).
+
+A more reliable way of determining number of ports is to check for the
+last set bit in the "enabled_ports" bitfield.
+
+This fixes b53 internal state, it will allow providing accurate info to
+the DSA and is required to fix BCM5301x support.
+
+Fixes: 967dd82ffc52 ("net: dsa: b53: Add support for Broadcom RoboSwitch")
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/dsa/b53/b53_common.c | 3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+--- a/drivers/net/dsa/b53/b53_common.c
++++ b/drivers/net/dsa/b53/b53_common.c
+@@ -2584,9 +2584,8 @@ static int b53_switch_init(struct b53_de
+ 			dev->cpu_port = 5;
+ 	}
+ 
+-	/* cpu port is always last */
+-	dev->num_ports = dev->cpu_port + 1;
+ 	dev->enabled_ports |= BIT(dev->cpu_port);
++	dev->num_ports = fls(dev->enabled_ports);
+ 
+ 	/* Include non standard CPU port built-in PHYs to be probed */
+ 	if (is539x(dev) || is531x5(dev)) {