From 30985e3beb739c37b8879fe4e1cd4791260b94ce Mon Sep 17 00:00:00 2001 From: Lars Persson Date: Fri, 1 Dec 2017 11:12:44 +0100 Subject: [PATCH] stmmac: reset last TSO segment size after device open [ Upstream commit 45ab4b13e46325d00f4acdb365d406e941a15f81 ] The mss variable tracks the last max segment size sent to the TSO engine. We do not update the hardware as long as we receive skb:s with the same value in gso_size. During a network device down/up cycle (mapped to stmmac_release() and stmmac_open() callbacks) we issue a reset to the hardware and it forgets the setting for mss. However we did not zero out our mss variable so the next transmission of a gso packet happens with an undefined hardware setting. This triggers a hang in the TSO engine and eventuelly the netdev watchdog will bark. Fixes: f748be531d70 ("stmmac: support new GMAC4") Signed-off-by: Lars Persson Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index ef6bff820cf6..adf61a7b1b01 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -1795,6 +1795,7 @@ static int stmmac_open(struct net_device *dev) priv->dma_buf_sz = STMMAC_ALIGN(buf_sz); priv->rx_copybreak = STMMAC_RX_COPYBREAK; + priv->mss = 0; ret = alloc_dma_desc_resources(priv); if (ret < 0) { -- 2.17.1