diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 2c68b1a60887a..20595b7141af1 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -379,16 +379,6 @@ m_can_txe_fifo_read(struct m_can_classdev *cdev, u32 fgi, u32 offset, u32 *val) return cdev->ops->read_fifo(cdev, addr_offset, val, 1); } -static inline bool _m_can_tx_fifo_full(u32 txfqs) -{ - return !!(txfqs & TXFQS_TFQF); -} - -static inline bool m_can_tx_fifo_full(struct m_can_classdev *cdev) -{ - return _m_can_tx_fifo_full(m_can_read(cdev, M_CAN_TXFQS)); -} - static void m_can_config_endisable(struct m_can_classdev *cdev, bool enable) { u32 cccr = m_can_read(cdev, M_CAN_CCCR); @@ -1077,17 +1067,31 @@ static void m_can_finish_tx(struct m_can_classdev *cdev, int transmitted) unsigned long irqflags; spin_lock_irqsave(&cdev->tx_handling_spinlock, irqflags); + if (cdev->tx_fifo_in_flight >= cdev->tx_fifo_size && transmitted > 0) + netif_wake_queue(cdev->net); cdev->tx_fifo_in_flight -= transmitted; spin_unlock_irqrestore(&cdev->tx_handling_spinlock, irqflags); } -static void m_can_start_tx(struct m_can_classdev *cdev) +static netdev_tx_t m_can_start_tx(struct m_can_classdev *cdev) { unsigned long irqflags; + int tx_fifo_in_flight; spin_lock_irqsave(&cdev->tx_handling_spinlock, irqflags); - ++cdev->tx_fifo_in_flight; + tx_fifo_in_flight = cdev->tx_fifo_in_flight + 1; + if (tx_fifo_in_flight >= cdev->tx_fifo_size) { + netif_stop_queue(cdev->net); + if (tx_fifo_in_flight > cdev->tx_fifo_size) { + netdev_err_once(cdev->net, "hard_xmit called while TX FIFO full\n"); + spin_unlock_irqrestore(&cdev->tx_handling_spinlock, irqflags); + return NETDEV_TX_BUSY; + } + } + cdev->tx_fifo_in_flight = tx_fifo_in_flight; spin_unlock_irqrestore(&cdev->tx_handling_spinlock, irqflags); + + return NETDEV_TX_OK; } static int m_can_echo_tx_event(struct net_device *dev) @@ -1218,7 +1222,6 @@ static irqreturn_t m_can_isr(int irq, void *dev_id) if (cdev->is_peripheral) timestamp = m_can_get_timestamp(cdev); m_can_tx_update_stats(cdev, 0, timestamp); - netif_wake_queue(dev); m_can_finish_tx(cdev, 1); } } else { @@ -1226,10 +1229,6 @@ static irqreturn_t m_can_isr(int irq, void *dev_id) /* New TX FIFO Element arrived */ if (m_can_echo_tx_event(dev) != 0) goto out_fail; - - if (netif_queue_stopped(dev) && - !m_can_tx_fifo_full(cdev)) - netif_wake_queue(dev); } } @@ -1729,20 +1728,6 @@ static int m_can_close(struct net_device *dev) return 0; } -static int m_can_next_echo_skb_occupied(struct net_device *dev, u32 putidx) -{ - struct m_can_classdev *cdev = netdev_priv(dev); - /*get wrap around for loopback skb index */ - unsigned int wrap = cdev->can.echo_skb_max; - u32 next_idx; - - /* calculate next index */ - next_idx = (++putidx >= wrap ? 0 : putidx); - - /* check if occupied */ - return !!cdev->can.echo_skb[next_idx]; -} - static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev, struct sk_buff *skb) { @@ -1751,7 +1736,6 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev, struct m_can_fifo_element fifo_element; struct net_device *dev = cdev->net; u32 cccr, fdflags; - u32 txfqs; int err; u32 putidx; @@ -1806,24 +1790,6 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev, } else { /* Transmit routine for version >= v3.1.x */ - txfqs = m_can_read(cdev, M_CAN_TXFQS); - - /* Check if FIFO full */ - if (_m_can_tx_fifo_full(txfqs)) { - /* This shouldn't happen */ - netif_stop_queue(dev); - netdev_warn(dev, - "TX queue active although FIFO is full."); - - if (cdev->is_peripheral) { - kfree_skb(skb); - dev->stats.tx_dropped++; - return NETDEV_TX_OK; - } else { - return NETDEV_TX_BUSY; - } - } - /* get put index for frame */ putidx = cdev->tx_fifo_putidx; @@ -1861,11 +1827,6 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev, m_can_write(cdev, M_CAN_TXBAR, (1 << putidx)); cdev->tx_fifo_putidx = (++cdev->tx_fifo_putidx >= cdev->can.echo_skb_max ? 0 : cdev->tx_fifo_putidx); - - /* stop network queue if fifo full */ - if (m_can_tx_fifo_full(cdev) || - m_can_next_echo_skb_occupied(dev, putidx)) - netif_stop_queue(dev); } return NETDEV_TX_OK; @@ -1899,7 +1860,6 @@ static void m_can_tx_queue_skb(struct m_can_classdev *cdev, struct sk_buff *skb) static netdev_tx_t m_can_start_peripheral_xmit(struct m_can_classdev *cdev, struct sk_buff *skb) { - netif_stop_queue(cdev->net); m_can_tx_queue_skb(cdev, skb); return NETDEV_TX_OK; @@ -1909,6 +1869,7 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct m_can_classdev *cdev = netdev_priv(dev); + netdev_tx_t ret; if (can_dev_dropped_skb(dev, skb)) return NETDEV_TX_OK; @@ -1918,7 +1879,9 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb, return NETDEV_TX_OK; } - m_can_start_tx(cdev); + ret = m_can_start_tx(cdev); + if (ret != NETDEV_TX_OK) + return ret; if (cdev->is_peripheral) return m_can_start_peripheral_xmit(cdev, skb);