[openwrt/openwrt] realtek: don't set L2LEARNING flag in rtl83xx TX header

[LEDE Commits]

svanheule pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/c94ca63ed4eed9aa92dc2fa4d61235b6845b42d3

commit c94ca63ed4eed9aa92dc2fa4d61235b6845b42d3
Author: Jan Hoffmann <jan at 3e8.eu>
AuthorDate: Sat Dec 17 21:39:40 2022 +0100

    realtek: don't set L2LEARNING flag in rtl83xx TX header
    
    As learning for the CPU port is now disabled globally, the bit in the
    TX header doesn't have any effect anymore. Remove it to make the header
    consistent with the global configuration.
    
    Originally, this change was intended to be applied before commit
    eb456aedfe24 ("realtek: use assisted learning on CPU port"), which is
    why the commit message incorrectly mentions that the TX header already
    disables learning.
    
    The reason for disabling learning on the CPU port in the first place is
    that it doesn't work correctly when packets are trapped to the CPU and
    then forwarded by the CPU to other ports. In that case, the switch would
    incorrectly learn the CPU port as source. An example that triggered this
    issue are Multicast Listener Reports and IGMP membership reports.
    
    Signed-off-by: Jan Hoffmann <jan at 3e8.eu>
---
 target/linux/realtek/files-5.10/drivers/net/ethernet/rtl838x_eth.c | 4 ++--
 target/linux/realtek/files-5.15/drivers/net/ethernet/rtl838x_eth.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/target/linux/realtek/files-5.10/drivers/net/ethernet/rtl838x_eth.c b/target/linux/realtek/files-5.10/drivers/net/ethernet/rtl838x_eth.c
index 166e49e139..32de5cc554 100644
--- a/target/linux/realtek/files-5.10/drivers/net/ethernet/rtl838x_eth.c
+++ b/target/linux/realtek/files-5.10/drivers/net/ethernet/rtl838x_eth.c
@@ -96,7 +96,7 @@ struct notify_b {
 static void rtl838x_create_tx_header(struct p_hdr *h, unsigned int dest_port, int prio)
 {
 	// cpu_tag[0] is reserved on the RTL83XX SoCs
-	h->cpu_tag[1] = 0x0401;  // BIT 10: RTL8380_CPU_TAG, BIT0: L2LEARNING on
+	h->cpu_tag[1] = 0x0400;  // BIT 10: RTL8380_CPU_TAG
 	h->cpu_tag[2] = 0x0200;  // Set only AS_DPM, to enable DPM settings below
 	h->cpu_tag[3] = 0x0000;
 	h->cpu_tag[4] = BIT(dest_port) >> 16;
@@ -111,7 +111,7 @@ static void rtl839x_create_tx_header(struct p_hdr *h, unsigned int dest_port, in
 {
 	// cpu_tag[0] is reserved on the RTL83XX SoCs
 	h->cpu_tag[1] = 0x0100; // RTL8390_CPU_TAG marker
-	h->cpu_tag[2] = BIT(4) | BIT(7); /* AS_DPM (4) and L2LEARNING (7) flags */
+	h->cpu_tag[2] = BIT(4); /* AS_DPM flag */
 	h->cpu_tag[3] = h->cpu_tag[4] = h->cpu_tag[5] = 0;
 	// h->cpu_tag[1] |= BIT(1) | BIT(0); // Bypass filter 1/2
 	if (dest_port >= 32) {
diff --git a/target/linux/realtek/files-5.15/drivers/net/ethernet/rtl838x_eth.c b/target/linux/realtek/files-5.15/drivers/net/ethernet/rtl838x_eth.c
index 166e49e139..32de5cc554 100644
--- a/target/linux/realtek/files-5.15/drivers/net/ethernet/rtl838x_eth.c
+++ b/target/linux/realtek/files-5.15/drivers/net/ethernet/rtl838x_eth.c
@@ -96,7 +96,7 @@ struct notify_b {
 static void rtl838x_create_tx_header(struct p_hdr *h, unsigned int dest_port, int prio)
 {
 	// cpu_tag[0] is reserved on the RTL83XX SoCs
-	h->cpu_tag[1] = 0x0401;  // BIT 10: RTL8380_CPU_TAG, BIT0: L2LEARNING on
+	h->cpu_tag[1] = 0x0400;  // BIT 10: RTL8380_CPU_TAG
 	h->cpu_tag[2] = 0x0200;  // Set only AS_DPM, to enable DPM settings below
 	h->cpu_tag[3] = 0x0000;
 	h->cpu_tag[4] = BIT(dest_port) >> 16;
@@ -111,7 +111,7 @@ static void rtl839x_create_tx_header(struct p_hdr *h, unsigned int dest_port, in
 {
 	// cpu_tag[0] is reserved on the RTL83XX SoCs
 	h->cpu_tag[1] = 0x0100; // RTL8390_CPU_TAG marker
-	h->cpu_tag[2] = BIT(4) | BIT(7); /* AS_DPM (4) and L2LEARNING (7) flags */
+	h->cpu_tag[2] = BIT(4); /* AS_DPM flag */
 	h->cpu_tag[3] = h->cpu_tag[4] = h->cpu_tag[5] = 0;
 	// h->cpu_tag[1] |= BIT(1) | BIT(0); // Bypass filter 1/2
 	if (dest_port >= 32) {