Messages in this thread | | | Date | Thu, 24 Feb 2022 15:53:33 +0300 | Subject | Re: [PATCH v2] net: stmmac: only enable DMA interrupts when ready | From | Denis Kirjanov <> |
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2/24/22 14:38, Vincent Whitchurch пишет: > In this driver's ->ndo_open() callback, it enables DMA interrupts, > starts the DMA channels, then requests interrupts with request_irq(), > and then finally enables napi. > > If RX DMA interrupts are received before napi is enabled, no processing > is done because napi_schedule_prep() will return false. If the network > has a lot of broadcast/multicast traffic, then the RX ring could fill up > completely before napi is enabled. When this happens, no further RX > interrupts will be delivered, and the driver will fail to receive any > packets. > > Fix this by only enabling DMA interrupts after all other initialization > is complete. > > Fixes: 523f11b5d4fd72efb ("net: stmmac: move hardware setup for stmmac_open to new function") > Reported-by: Lars Persson <larper@axis.com> > Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> > --- > .../net/ethernet/stmicro/stmmac/stmmac_main.c | 28 +++++++++++++++++-- > 1 file changed, 26 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > index 6708ca2aa4f7..43978558d6c0 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > @@ -2260,6 +2260,23 @@ static void stmmac_stop_tx_dma(struct stmmac_priv *priv, u32 chan) > stmmac_stop_tx(priv, priv->ioaddr, chan); > } > > +static void stmmac_enable_all_dma_irq(struct stmmac_priv *priv) > +{ > + u32 rx_channels_count = priv->plat->rx_queues_to_use; > + u32 tx_channels_count = priv->plat->tx_queues_to_use; > + u32 dma_csr_ch = max(rx_channels_count, tx_channels_count); > + u32 chan; > + > + for (chan = 0; chan < dma_csr_ch; chan++) { > + struct stmmac_channel *ch = &priv->channel[chan]; > + unsigned long flags; > + > + spin_lock_irqsave(&ch->lock, flags); > + stmmac_enable_dma_irq(priv, priv->ioaddr, chan, 1, 1); > + spin_unlock_irqrestore(&ch->lock, flags); > + } > +} > + > /** > * stmmac_start_all_dma - start all RX and TX DMA channels > * @priv: driver private structure > @@ -2902,8 +2919,10 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv) > stmmac_axi(priv, priv->ioaddr, priv->plat->axi); > > /* DMA CSR Channel configuration */ > - for (chan = 0; chan < dma_csr_ch; chan++) > + for (chan = 0; chan < dma_csr_ch; chan++) { > stmmac_init_chan(priv, priv->ioaddr, priv->plat->dma_cfg, chan); Did you miss to take a channel lock? > + stmmac_disable_dma_irq(priv, priv->ioaddr, chan, 1, 1); > + } > > /* DMA RX Channel Configuration */ > for (chan = 0; chan < rx_channels_count; chan++) { > @@ -3759,6 +3778,7 @@ static int stmmac_open(struct net_device *dev) > > stmmac_enable_all_queues(priv); > netif_tx_start_all_queues(priv->dev); > + stmmac_enable_all_dma_irq(priv); > > return 0; > > @@ -6508,8 +6528,10 @@ int stmmac_xdp_open(struct net_device *dev) > } > > /* DMA CSR Channel configuration */ > - for (chan = 0; chan < dma_csr_ch; chan++) > + for (chan = 0; chan < dma_csr_ch; chan++) { > stmmac_init_chan(priv, priv->ioaddr, priv->plat->dma_cfg, chan); > + stmmac_disable_dma_irq(priv, priv->ioaddr, chan, 1, 1); > + } > > /* Adjust Split header */ > sph_en = (priv->hw->rx_csum > 0) && priv->sph; > @@ -6570,6 +6592,7 @@ int stmmac_xdp_open(struct net_device *dev) > stmmac_enable_all_queues(priv); > netif_carrier_on(dev); > netif_tx_start_all_queues(dev); > + stmmac_enable_all_dma_irq(priv); > > return 0; > > @@ -7447,6 +7470,7 @@ int stmmac_resume(struct device *dev) > stmmac_restore_hw_vlan_rx_fltr(priv, ndev, priv->hw); > > stmmac_enable_all_queues(priv); > + stmmac_enable_all_dma_irq(priv); > > mutex_unlock(&priv->lock); > rtnl_unlock();
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