On 16:17 Mon 19 Nov , Nicolas Ferre wrote: > Move to circular buffers management macro and correct an error > with circular buffer initial condition. > > Without this patch, the macb_tx_ring_avail() function was > not reporting the proper ring availability at startup: > macb macb: eth0: BUG! Tx Ring full when queue awake! > macb macb: eth0: tx_head = 0, tx_tail = 0 > And hanginig forever... > > I remove the macb_tx_ring_avail() function and use the > proven macros from circ_buf.h. CIRC_CNT() is used in the > "consumer" part of the driver: macb_tx_interrupt() to match > advice from Documentation/circular-buffers.txt. > > Signed-off-by: Nicolas Ferre <[email protected]>
Just tested on 9260 Tested-by: Jean-Christophe PLAGNIOL-VILLARD <[email protected]> Best Regards, J. > --- > drivers/net/ethernet/cadence/macb.c | 17 +++++++---------- > 1 file changed, 7 insertions(+), 10 deletions(-) > > diff --git a/drivers/net/ethernet/cadence/macb.c > b/drivers/net/ethernet/cadence/macb.c > index edb2aba..27991dd 100644 > --- a/drivers/net/ethernet/cadence/macb.c > +++ b/drivers/net/ethernet/cadence/macb.c > @@ -14,6 +14,7 @@ > #include <linux/moduleparam.h> > #include <linux/kernel.h> > #include <linux/types.h> > +#include <linux/circ_buf.h> > #include <linux/slab.h> > #include <linux/init.h> > #include <linux/gpio.h> > @@ -38,8 +39,8 @@ > #define TX_RING_SIZE 128 /* must be power of 2 */ > #define TX_RING_BYTES (sizeof(struct macb_dma_desc) * > TX_RING_SIZE) > > -/* minimum number of free TX descriptors before waking up TX process */ > -#define MACB_TX_WAKEUP_THRESH (TX_RING_SIZE / 4) > +/* level of occupied TX descriptors under which we wake up TX process */ > +#define MACB_TX_WAKEUP_THRESH (3 * TX_RING_SIZE / 4) > > #define MACB_RX_INT_FLAGS (MACB_BIT(RCOMP) | MACB_BIT(RXUBR) \ > | MACB_BIT(ISR_ROVR)) > @@ -60,11 +61,6 @@ static unsigned int macb_tx_ring_wrap(unsigned int index) > return index & (TX_RING_SIZE - 1); > } > > -static unsigned int macb_tx_ring_avail(struct macb *bp) > -{ > - return (bp->tx_tail - bp->tx_head) & (TX_RING_SIZE - 1); > -} > - > static struct macb_dma_desc *macb_tx_desc(struct macb *bp, unsigned int > index) > { > return &bp->tx_ring[macb_tx_ring_wrap(index)]; > @@ -524,7 +520,8 @@ static void macb_tx_interrupt(struct macb *bp) > > bp->tx_tail = tail; > if (netif_queue_stopped(bp->dev) > - && macb_tx_ring_avail(bp) > MACB_TX_WAKEUP_THRESH) > + && CIRC_CNT(bp->tx_head, bp->tx_tail, > + TX_RING_SIZE) <= MACB_TX_WAKEUP_THRESH) > netif_wake_queue(bp->dev); > } > > @@ -818,7 +815,7 @@ static int macb_start_xmit(struct sk_buff *skb, struct > net_device *dev) > spin_lock_irqsave(&bp->lock, flags); > > /* This is a hard error, log it. */ > - if (macb_tx_ring_avail(bp) < 1) { > + if (CIRC_SPACE(bp->tx_head, bp->tx_tail, TX_RING_SIZE) < 1) { > netif_stop_queue(dev); > spin_unlock_irqrestore(&bp->lock, flags); > netdev_err(bp->dev, "BUG! Tx Ring full when queue awake!\n"); > @@ -855,7 +852,7 @@ static int macb_start_xmit(struct sk_buff *skb, struct > net_device *dev) > > macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(TSTART)); > > - if (macb_tx_ring_avail(bp) < 1) > + if (CIRC_SPACE(bp->tx_head, bp->tx_tail, TX_RING_SIZE) < 1) > netif_stop_queue(dev); > > spin_unlock_irqrestore(&bp->lock, flags); > -- > 1.8.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
