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Date:   Wed, 12 Aug 2020 20:37:23 +0100
From:   Jonathan McDowell <noodles@earth.li>
To:     Giuseppe Cavallaro <peppe.cavallaro@st.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Jose Abreu <joabreu@synopsys.com>,
        David Miller <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net 2/2] net: ethernet: stmmac: Disable hardware multicast
 filter
Message-ID: <dc3426bce09689ea2ba5b3a1937d6a77049089f1.1597260787.git.noodles@earth.li>
References: <cover.1597260787.git.noodles@earth.li>
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The IPQ806x does not appear to have a functional multicast ethernet
address filter. This was observed as a failure to correctly receive IPv6
packets on a LAN to the all stations address. Checking the vendor driver
shows that it does not attempt to enable the multicast filter and
instead falls back to receiving all multicast packets, internally
setting ALLMULTI.

Use the new fallback support in the dwmac1000 driver to correctly
achieve the same with the mainline IPQ806x driver. Confirmed to fix IPv6
functionality on an RB3011 router.

Cc: stable@vger.kernel.org
Signed-off-by: Jonathan McDowell <noodles@earth.li>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
index 02102c781a8c..bf3250e0e59c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
@@ -351,6 +351,7 @@ static int ipq806x_gmac_probe(struct platform_device *pdev)
 	plat_dat->has_gmac = true;
 	plat_dat->bsp_priv = gmac;
 	plat_dat->fix_mac_speed = ipq806x_gmac_fix_mac_speed;
+	plat_dat->multicast_filter_bins = 0;
 
 	err = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
 	if (err)
-- 
2.20.1