net: dsa: b53: prevent SWITCH_CTRL access on BCM5325

[ Upstream commit 22ccaaca43440e90a3b68d2183045b42247dc4be ]

BCM5325 doesn't implement SWITCH_CTRL register so we should avoid reading
or writing it.

Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Link: https://patch.msgid.link/20250614080000.1884236-8-noltari@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index 1ee2e5e9a5b20af2ce08af38b4c212edbd23d656..aacdfc64d3b6bc07f760e6365bec2388499c774b 100644 (file)
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -359,11 +359,12 @@ static void b53_set_forwarding(struct b53_device *dev, int enable)
 
        b53_write8(dev, B53_CTRL_PAGE, B53_SWITCH_MODE, mgmt);
 
-       /* Include IMP port in dumb forwarding mode
-        */
-       b53_read8(dev, B53_CTRL_PAGE, B53_SWITCH_CTRL, &mgmt);
-       mgmt |= B53_MII_DUMB_FWDG_EN;
-       b53_write8(dev, B53_CTRL_PAGE, B53_SWITCH_CTRL, mgmt);
+       if (!is5325(dev)) {
+               /* Include IMP port in dumb forwarding mode */
+               b53_read8(dev, B53_CTRL_PAGE, B53_SWITCH_CTRL, &mgmt);
+               mgmt |= B53_MII_DUMB_FWDG_EN;
+               b53_write8(dev, B53_CTRL_PAGE, B53_SWITCH_CTRL, mgmt);
+       }
 
        /* Look at B53_UC_FWD_EN and B53_MC_FWD_EN to decide whether
         * frames should be flooded or not.