diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c index 3772804fb6970cc1f2b6f6f14807d4f6573c52a2..b35e6a76664cec1882ad7c552c43524a3973f9c6 100644 --- a/drivers/net/ethernet/ti/cpsw.c +++ b/drivers/net/ethernet/ti/cpsw.c @@ -374,6 +374,9 @@ void cpsw_tx_handler(void *token, int len, int status) struct net_device *ndev = skb->dev; struct cpsw_priv *priv = netdev_priv(ndev); + /* Check whether the queue is stopped due to stalled tx dma, if the + * queue is stopped then start the queue as we have free desc for tx + */ if (unlikely(netif_queue_stopped(ndev))) netif_start_queue(ndev); cpts_tx_timestamp(&priv->cpts, skb); @@ -736,6 +739,12 @@ static netdev_tx_t cpsw_ndo_start_xmit(struct sk_buff *skb, goto fail; } + /* If there is no more tx desc left free then we need to + * tell the kernel to stop sending us tx frames. + */ + if (unlikely(cpdma_check_free_tx_desc(priv->txch))) + netif_stop_queue(ndev); + return NETDEV_TX_OK; fail: priv->stats.tx_dropped++; diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c index 49956730cd8db884ac1696d108cb62fe61d49533..f8629186afbe7df4dacff3101be24582eb140cef 100644 --- a/drivers/net/ethernet/ti/davinci_cpdma.c +++ b/drivers/net/ethernet/ti/davinci_cpdma.c @@ -105,13 +105,13 @@ struct cpdma_ctlr { }; struct cpdma_chan { + struct cpdma_desc __iomem *head, *tail; + void __iomem *hdp, *cp, *rxfree; enum cpdma_state state; struct cpdma_ctlr *ctlr; int chan_num; spinlock_t lock; - struct cpdma_desc __iomem *head, *tail; int count; - void __iomem *hdp, *cp, *rxfree; u32 mask; cpdma_handler_fn handler; enum dma_data_direction dir; @@ -217,17 +217,27 @@ desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma) } static struct cpdma_desc __iomem * -cpdma_desc_alloc(struct cpdma_desc_pool *pool, int num_desc) +cpdma_desc_alloc(struct cpdma_desc_pool *pool, int num_desc, bool is_rx) { unsigned long flags; int index; + int desc_start; + int desc_end; struct cpdma_desc __iomem *desc = NULL; spin_lock_irqsave(&pool->lock, flags); - index = bitmap_find_next_zero_area(pool->bitmap, pool->num_desc, 0, - num_desc, 0); - if (index < pool->num_desc) { + if (is_rx) { + desc_start = 0; + desc_end = pool->num_desc/2; + } else { + desc_start = pool->num_desc/2; + desc_end = pool->num_desc; + } + + index = bitmap_find_next_zero_area(pool->bitmap, + desc_end, desc_start, num_desc, 0); + if (index < desc_end) { bitmap_set(pool->bitmap, index, num_desc); desc = pool->iomap + pool->desc_size * index; pool->used_desc++; @@ -668,7 +678,7 @@ int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data, goto unlock_ret; } - desc = cpdma_desc_alloc(ctlr->pool, 1); + desc = cpdma_desc_alloc(ctlr->pool, 1, is_rx_chan(chan)); if (!desc) { chan->stats.desc_alloc_fail++; ret = -ENOMEM; @@ -704,6 +714,29 @@ int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data, } EXPORT_SYMBOL_GPL(cpdma_chan_submit); +bool cpdma_check_free_tx_desc(struct cpdma_chan *chan) +{ + unsigned long flags; + int index; + bool ret; + struct cpdma_ctlr *ctlr = chan->ctlr; + struct cpdma_desc_pool *pool = ctlr->pool; + + spin_lock_irqsave(&pool->lock, flags); + + index = bitmap_find_next_zero_area(pool->bitmap, + pool->num_desc, pool->num_desc/2, 1, 0); + + if (index < pool->num_desc) + ret = true; + else + ret = false; + + spin_unlock_irqrestore(&pool->lock, flags); + return ret; +} +EXPORT_SYMBOL_GPL(cpdma_check_free_tx_desc); + static void __cpdma_chan_free(struct cpdma_chan *chan, struct cpdma_desc __iomem *desc, int outlen, int status) diff --git a/drivers/net/ethernet/ti/davinci_cpdma.h b/drivers/net/ethernet/ti/davinci_cpdma.h index afa19a0c0d81000d265a8930c9ecec7220863518..8d2aeb2096ac9c3f34df4bf775fa24acd5814012 100644 --- a/drivers/net/ethernet/ti/davinci_cpdma.h +++ b/drivers/net/ethernet/ti/davinci_cpdma.h @@ -88,6 +88,7 @@ int cpdma_chan_process(struct cpdma_chan *chan, int quota); int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable); void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr); int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable); +bool cpdma_check_free_tx_desc(struct cpdma_chan *chan); enum cpdma_control { CPDMA_CMD_IDLE, /* write-only */ diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c index 8478d98c10929043dc8837fe21fdb7fec22882c7..1c97c8171d3efa9d6a45ea6622506176301d19a5 100644 --- a/drivers/net/ethernet/ti/davinci_emac.c +++ b/drivers/net/ethernet/ti/davinci_emac.c @@ -120,7 +120,6 @@ static const char emac_version_string[] = "TI DaVinci EMAC Linux v6.1"; #define EMAC_DEF_TX_CH (0) /* Default 0th channel */ #define EMAC_DEF_RX_CH (0) /* Default 0th channel */ #define EMAC_DEF_RX_NUM_DESC (128) -#define EMAC_DEF_TX_NUM_DESC (128) #define EMAC_DEF_MAX_TX_CH (1) /* Max TX channels configured */ #define EMAC_DEF_MAX_RX_CH (1) /* Max RX channels configured */ #define EMAC_POLL_WEIGHT (64) /* Default NAPI poll weight */ @@ -342,7 +341,6 @@ struct emac_priv { u32 mac_hash2; u32 multicast_hash_cnt[EMAC_NUM_MULTICAST_BITS]; u32 rx_addr_type; - atomic_t cur_tx; const char *phy_id; #ifdef CONFIG_OF struct device_node *phy_node; @@ -1050,10 +1048,10 @@ static void emac_tx_handler(void *token, int len, int status) { struct sk_buff *skb = token; struct net_device *ndev = skb->dev; - struct emac_priv *priv = netdev_priv(ndev); - - atomic_dec(&priv->cur_tx); + /* Check whether the queue is stopped due to stalled tx dma, if the + * queue is stopped then start the queue as we have free desc for tx + */ if (unlikely(netif_queue_stopped(ndev))) netif_start_queue(ndev); ndev->stats.tx_packets++; @@ -1101,7 +1099,10 @@ static int emac_dev_xmit(struct sk_buff *skb, struct net_device *ndev) goto fail_tx; } - if (atomic_inc_return(&priv->cur_tx) >= EMAC_DEF_TX_NUM_DESC) + /* If there is no more tx desc left free then we need to + * tell the kernel to stop sending us tx frames. + */ + if (unlikely(cpdma_check_free_tx_desc(priv->txch))) netif_stop_queue(ndev); return NETDEV_TX_OK;