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authorLars Persson <lars.persson@axis.com>2019-04-15 09:49:47 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-20 09:15:10 +0200
commit5661213956662f592979925eab1e4dfff955ba05 (patch)
parent03f11a51a196a9aadc20a70a73825a811a726218 (diff)
net: stmmac: Set dma ring length before enabling the DMA
This was fixed in upstream by commit 7d9e6c5afab6 ("net: stmmac: Integrate XGMAC into main driver flow") that is a new feature commit. We found a race condition in the DMA init sequence that hits if the PHY already has link up during stmmac_hw_setup. Since the ring length was programmed after enabling the RX path, we might receive a packet before the correct ring length is programmed. When that happened we could not get reliable interrupts for DMA RX and the MTL complained about RX FIFO overrun. Signed-off-by: Lars Persson <larper@axis.com> Cc: stable@vger.kernel.org # 4.14.x Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: Jose Abreu <joabreu@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 4a9dbee6f054..f2429ec07b57 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2536,9 +2536,6 @@ static int stmmac_hw_setup(struct net_device *dev, bool init_ptp)
netdev_warn(priv->dev, "%s: failed debugFS registration\n",
- /* Start the ball rolling... */
- stmmac_start_all_dma(priv);
priv->tx_lpi_timer = STMMAC_DEFAULT_TWT_LS;
if ((priv->use_riwt) && (priv->hw->dma->rx_watchdog)) {
@@ -2558,6 +2555,9 @@ static int stmmac_hw_setup(struct net_device *dev, bool init_ptp)
priv->hw->dma->enable_tso(priv->ioaddr, 1, chan);
+ /* Start the ball rolling... */
+ stmmac_start_all_dma(priv);
return 0;