FAILED: patch "[PATCH] net: dsa: tag_ocelot: use traffic class to map priority on" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ae2778a64724f77fd6cad674461a045fb3307df7 Mon Sep 17 00:00:00 2001
From: Xiaoliang Yang <[email protected]>
Date: Thu, 23 Dec 2021 15:22:11 +0800
Subject: [PATCH] net: dsa: tag_ocelot: use traffic class to map priority on
injected header

For Ocelot switches, the CPU injected frames have an injection header where it can specify the QoS class of the packet and the DSA tag, now it uses the SKB priority to set that. If a traffic class to priority mapping is configured on the netdevice (with mqprio for example ...), it won't be considered for CPU injected headers. This patch make the QoS class aligned to the priority to traffic class mapping if it exists.

index de1c849a0a70..4ed74d509d6a 100644
@@ -47,9 +47,13 @@ static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
 	void *injection;
 	__be32 *prefix;
 	u32 rew_op = 0;
+	u64 qos_class;
 
 	ocelot_xmit_get_vlan_info(skb, dp, &vlan_tci, &tag_type);
 
+	qos_class = netdev_get_num_tc(netdev) ?
+		    netdev_get_prio_tc_map(netdev, skb->priority) : skb->priority;
+
 	injection = skb_push(skb, OCELOT_TAG_LEN);
 	prefix = skb_push(skb, OCELOT_SHORT_PREFIX_LEN);
 

@@ -57,7 +61,7 @@ static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
 	memset(injection, 0, OCELOT_TAG_LEN);
 	ocelot_ifh_set_bypass(injection, 1);
 	ocelot_ifh_set_src(injection, ds->num_ports);
-	ocelot_ifh_set_qos_class(injection, skb->priority);
+	ocelot_ifh_set_qos_class(injection, qos_class);
 	ocelot_ifh_set_vlan_tci(injection, vlan_tci);
 	ocelot_ifh_set_tag_type(injection, tag_type);