net: dsa: lantiq_gswip: clarify GSWIP 2.2 VLAN mode in comment

The comment above writing the default PVID incorrectly states that
"GSWIP 2.2 (GRX300) and later program here the VID directly."
The truth is that even GSWIP 2.2 and newer maintain the behavior of
GSWIP 2.1 unless the VLANMD bit in PCE Global Control Register 1 is
set ("GSWIP2.2 VLAN Mode").
Fix the misleading comment accordingly.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Acked-by; Hauke Mehrtens <hauke@hauke-m.de>:
Acked-by; Hauke Mehrtens <hauke@hauke-m.de>:
Link: https://patch.msgid.link/018056a575503d9797f3222f71a988e825316be0.1761045000.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/dsa/lantiq/lantiq_gswip.c b/drivers/net/dsa/lantiq/lantiq_gswip.c
index 25f6b46957a01f7a449a7125d33daf68b7ae6425..86b410a40d32cc065c2f780ad52171d5ae8c6ee9 100644 (file)
--- a/drivers/net/dsa/lantiq/lantiq_gswip.c
+++ b/drivers/net/dsa/lantiq/lantiq_gswip.c
@@ -588,7 +588,11 @@ static void gswip_port_commit_pvid(struct gswip_priv *priv, int port)
                          FIELD_PREP(GSWIP_PCE_VCTRL_VINR, vinr),
                          GSWIP_PCE_VCTRL(port));
 
-       /* GSWIP 2.2 (GRX300) and later program here the VID directly. */
+       /* Note that in GSWIP 2.2 VLAN mode the VID needs to be programmed
+        * directly instead of referencing the index in the Active VLAN Tablet.
+        * However, without the VLANMD bit (9) in PCE_GCTRL_1 (0x457) even
+        * GSWIP 2.2 and newer hardware maintain the GSWIP 2.1 behavior.
+        */
        gswip_switch_w(priv, idx, GSWIP_PCE_DEFPVID(port));
 }