net: dsa: b53: stop reading ARL entries if search is done

[ Upstream commit 0be04b5fa62a82a9929ca261f6c9f64a3d0a28da ]

The switch clears the ARL_SRCH_STDN bit when the search is done, i.e. it
finished traversing the ARL table.

This means that there will be no valid result, so we should not attempt
to read and process any further entries.

We only ever check the validity of the entries for 4 ARL bin chips, and
only after having passed the first entry to the b53_fdb_copy().

This means that we always pass an invalid entry at the end to the
b53_fdb_copy(). b53_fdb_copy() does check the validity though before
passing on the entry, so it never gets passed on.

On < 4 ARL bin chips, we will even continue reading invalid entries
until we reach the result limit.

Fixes: 1da6df85c6fb ("net: dsa: b53: Implement ARL add/del/dump operations")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20251102100758.28352-3-jonas.gorski@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 bc303b3e1c9663d67ea99573fd03d738ff9570cc..6a583e220bf841da30964e57bc3a0eba8ceb9ba5 100644 (file)
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1643,7 +1643,7 @@ static int b53_arl_search_wait(struct b53_device *dev)
        do {
                b53_read8(dev, B53_ARLIO_PAGE, B53_ARL_SRCH_CTL, &reg);
                if (!(reg & ARL_SRCH_STDN))
-                       return 0;
+                       return -ENOENT;
 
                if (reg & ARL_SRCH_VLID)
                        return 0;