From 8edf0047f4b8e03d94ef88f5a7dec146cce03a06 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Tue, 28 Oct 2014 11:12:00 -0700 Subject: [PATCH 1/2] net: systemport: enable RX interrupts after NAPI There is currently a small window during which the SYSTEMPORT adapter enables its RX interrupts without having enabled its NAPI handler, which can result in packets to be discarded during interface bringup. A similar but more serious window exists in bcm_sysport_resume() during which we can have the RDMA engine not fully prepared to receive packets and yet having RX interrupts enabled. Fix this my moving the RX interrupt enable down to bcm_sysport_netif_start() after napi_enable() for the RX path is called, which fixes both call sites: bcm_sysport_open() and bcm_sysport_resume(). Fixes: b02e6d9ba7ad ("net: systemport: add bcm_sysport_netif_{enable,stop}") Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/bcmsysport.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index 9ae36979bdee..7dce91189e51 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -1397,6 +1397,9 @@ static void bcm_sysport_netif_start(struct net_device *dev) /* Enable NAPI */ napi_enable(&priv->napi); + /* Enable RX interrupt and TX ring full interrupt */ + intrl2_0_mask_clear(priv, INTRL2_0_RDMA_MBDONE | INTRL2_0_TX_RING_FULL); + phy_start(priv->phydev); /* Enable TX interrupts for the 32 TXQs */ @@ -1499,9 +1502,6 @@ static int bcm_sysport_open(struct net_device *dev) if (ret) goto out_free_rx_ring; - /* Enable RX interrupt and TX ring full interrupt */ - intrl2_0_mask_clear(priv, INTRL2_0_RDMA_MBDONE | INTRL2_0_TX_RING_FULL); - /* Turn on TDMA */ ret = tdma_enable_set(priv, 1); if (ret) @@ -1885,9 +1885,6 @@ static int bcm_sysport_resume(struct device *d) netif_device_attach(dev); - /* Enable RX interrupt and TX ring full interrupt */ - intrl2_0_mask_clear(priv, INTRL2_0_RDMA_MBDONE | INTRL2_0_TX_RING_FULL); - /* RX pipe enable */ topctrl_writel(priv, 0, RX_FLUSH_CNTL); From 704d33e7006f20f9b4fa7d24a0f08c4b5919b131 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Tue, 28 Oct 2014 11:12:01 -0700 Subject: [PATCH 2/2] net: systemport: reset UniMAC coming out of a suspend cycle bcm_sysport_resume() was missing an UniMAC reset which can lead to various receive FIFO corruptions coming out of a suspend cycle. If the RX FIFO is stuck, it will deliver corrupted/duplicate packets towards the host CPU interface. This could be reproduced on crowded network and when Wake-on-LAN is enabled for this particular interface because the switch still forwards packets towards the host CPU interface (SYSTEMPORT), and we had to leave the UniMAC RX enable bit on to allow matching MagicPackets. Once we re-enter the resume function, there is a small window during which the UniMAC receive is still enabled, and we start queueing packets, but the RDMA and RBUF engines are not ready, which leads to having packets stuck in the UniMAC RX FIFO, ultimately delivered towards the host CPU as corrupted. Fixes: 40755a0fce17 ("net: systemport: add suspend and resume support") Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/bcmsysport.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index 7dce91189e51..3a6778a667f4 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -1858,6 +1858,8 @@ static int bcm_sysport_resume(struct device *d) if (!netif_running(dev)) return 0; + umac_reset(priv); + /* We may have been suspended and never received a WOL event that * would turn off MPD detection, take care of that now */