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Date:   Sat, 13 Mar 2021 13:18:26 +0000
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-kernel@vger.kernel.org
Subject: [PATCH net-next] net: stmmac: Set FIFO sizes for ipq806x
Message-ID: <20210313131826.GA17553@earth.li>
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Commit eaf4fac47807 ("net: stmmac: Do not accept invalid MTU values")
started using the TX FIFO size to verify what counts as a valid MTU
request for the stmmac driver.  This is unset for the ipq806x variant.
Looking at older patches for this it seems the RX + TXs buffers can be
up to 8k, so set appropriately.

(I sent this as an RFC patch in June last year, but received no replies.
I've been running with this on my hardware (a MikroTik RB3011) since
then with larger MTUs to support both the internal qca8k switch and
VLANs with no problems. Without the patch it's impossible to set the
larger MTU required to support this.)

Signed-off-by: Jonathan McDowell <noodles@earth.li>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
index bf3250e0e59c..749585fe6fc9 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
@@ -352,6 +352,8 @@ static int ipq806x_gmac_probe(struct platform_device *pdev)
 	plat_dat->bsp_priv = gmac;
 	plat_dat->fix_mac_speed = ipq806x_gmac_fix_mac_speed;
 	plat_dat->multicast_filter_bins = 0;
+	plat_dat->tx_fifo_size = 8192;
+	plat_dat->rx_fifo_size = 8192;
 
 	err = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
 	if (err)
-- 
2.30.1