#define MACB_RX_INT_FLAGS (MACB_BIT(RCOMP) | MACB_BIT(RXUBR) \
| MACB_BIT(ISR_ROVR))
+#define MACB_TX_ERR_FLAGS (MACB_BIT(ISR_TUND) \
+ | MACB_BIT(ISR_RLE) \
+ | MACB_BIT(TXERR))
+#define MACB_TX_INT_FLAGS (MACB_TX_ERR_FLAGS | MACB_BIT(TCOMP))
+
+/*
+ * Graceful stop timeouts in us. We should allow up to
+ * 1 frame time (10 Mbits/s, full-duplex, ignoring collisions)
+ */
+#define MACB_HALT_TIMEOUT 1230
/* Ring buffer accessors */
static unsigned int macb_tx_ring_wrap(unsigned int index)
*p += __raw_readl(reg);
}
-static void macb_tx(struct macb *bp)
+static int macb_halt_tx(struct macb *bp)
{
- unsigned int tail;
- unsigned int head;
- u32 status;
+ unsigned long halt_time, timeout;
+ u32 status;
- status = macb_readl(bp, TSR);
- macb_writel(bp, TSR, status);
+ macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(THALT));
- netdev_vdbg(bp->dev, "macb_tx status = 0x%03lx\n", (unsigned long)status);
+ timeout = jiffies + usecs_to_jiffies(MACB_HALT_TIMEOUT);
+ do {
+ halt_time = jiffies;
+ status = macb_readl(bp, TSR);
+ if (!(status & MACB_BIT(TGO)))
+ return 0;
- if (status & (MACB_BIT(UND) | MACB_BIT(TSR_RLE))) {
- int i;
- netdev_err(bp->dev, "TX %s, resetting buffers\n",
- status & MACB_BIT(UND) ?
- "underrun" : "retry limit exceeded");
+ usleep_range(10, 250);
+ } while (time_before(halt_time, timeout));
- /* Transfer ongoing, disable transmitter, to avoid confusion */
- if (status & MACB_BIT(TGO))
- macb_writel(bp, NCR, macb_readl(bp, NCR) & ~MACB_BIT(TE));
+ return -ETIMEDOUT;
+}
- head = bp->tx_head;
+static void macb_tx_error_task(struct work_struct *work)
+{
+ struct macb *bp = container_of(work, struct macb, tx_error_task);
+ struct macb_tx_skb *tx_skb;
+ struct sk_buff *skb;
+ unsigned int tail;
- /*Mark all the buffer as used to avoid sending a lost buffer*/
- for (i = 0; i < TX_RING_SIZE; i++)
- bp->tx_ring[i].ctrl = MACB_BIT(TX_USED);
+ netdev_vdbg(bp->dev, "macb_tx_error_task: t = %u, h = %u\n",
+ bp->tx_tail, bp->tx_head);
- /* Add wrap bit */
- bp->tx_ring[TX_RING_SIZE - 1].ctrl |= MACB_BIT(TX_WRAP);
+ /* Make sure nobody is trying to queue up new packets */
+ netif_stop_queue(bp->dev);
- /* free transmit buffer in upper layer*/
- for (tail = bp->tx_tail; tail != head; tail++) {
- struct macb_tx_skb *tx_skb;
- struct sk_buff *skb;
+ /*
+ * Stop transmission now
+ * (in case we have just queued new packets)
+ */
+ if (macb_halt_tx(bp))
+ /* Just complain for now, reinitializing TX path can be good */
+ netdev_err(bp->dev, "BUG: halt tx timed out\n");
- rmb();
+ /* No need for the lock here as nobody will interrupt us anymore */
- tx_skb = macb_tx_skb(bp, tail);
- skb = tx_skb->skb;
+ /*
+ * Treat frames in TX queue including the ones that caused the error.
+ * Free transmit buffers in upper layer.
+ */
+ for (tail = bp->tx_tail; tail != bp->tx_head; tail++) {
+ struct macb_dma_desc *desc;
+ u32 ctrl;
- dma_unmap_single(&bp->pdev->dev, tx_skb->mapping,
- skb->len, DMA_TO_DEVICE);
- tx_skb->skb = NULL;
- dev_kfree_skb_irq(skb);
- }
+ desc = macb_tx_desc(bp, tail);
+ ctrl = desc->ctrl;
+ tx_skb = macb_tx_skb(bp, tail);
+ skb = tx_skb->skb;
- bp->tx_head = bp->tx_tail = 0;
+ if (ctrl & MACB_BIT(TX_USED)) {
+ netdev_vdbg(bp->dev, "txerr skb %u (data %p) TX complete\n",
+ macb_tx_ring_wrap(tail), skb->data);
+ bp->stats.tx_packets++;
+ bp->stats.tx_bytes += skb->len;
+ } else {
+ /*
+ * "Buffers exhausted mid-frame" errors may only happen
+ * if the driver is buggy, so complain loudly about those.
+ * Statistics are updated by hardware.
+ */
+ if (ctrl & MACB_BIT(TX_BUF_EXHAUSTED))
+ netdev_err(bp->dev,
+ "BUG: TX buffers exhausted mid-frame\n");
- /* Enable the transmitter again */
- if (status & MACB_BIT(TGO))
- macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(TE));
+ desc->ctrl = ctrl | MACB_BIT(TX_USED);
+ }
+
+ dma_unmap_single(&bp->pdev->dev, tx_skb->mapping, skb->len,
+ DMA_TO_DEVICE);
+ tx_skb->skb = NULL;
+ dev_kfree_skb(skb);
}
- if (!(status & MACB_BIT(COMP)))
- /*
- * This may happen when a buffer becomes complete
- * between reading the ISR and scanning the
- * descriptors. Nothing to worry about.
- */
- return;
+ /* Make descriptor updates visible to hardware */
+ wmb();
+
+ /* Reinitialize the TX desc queue */
+ macb_writel(bp, TBQP, bp->tx_ring_dma);
+ /* Make TX ring reflect state of hardware */
+ bp->tx_head = bp->tx_tail = 0;
+
+ /* Now we are ready to start transmission again */
+ netif_wake_queue(bp->dev);
+
+ /* Housework before enabling TX IRQ */
+ macb_writel(bp, TSR, macb_readl(bp, TSR));
+ macb_writel(bp, IER, MACB_TX_INT_FLAGS);
+}
+
+static void macb_tx_interrupt(struct macb *bp)
+{
+ unsigned int tail;
+ unsigned int head;
+ u32 status;
+
+ status = macb_readl(bp, TSR);
+ macb_writel(bp, TSR, status);
+
+ netdev_vdbg(bp->dev, "macb_tx_interrupt status = 0x%03lx\n",
+ (unsigned long)status);
head = bp->tx_head;
for (tail = bp->tx_tail; tail != head; tail++) {
}
}
- if (status & (MACB_BIT(TCOMP) | MACB_BIT(ISR_TUND) |
- MACB_BIT(ISR_RLE)))
- macb_tx(bp);
+ if (unlikely(status & (MACB_TX_ERR_FLAGS))) {
+ macb_writel(bp, IDR, MACB_TX_INT_FLAGS);
+ schedule_work(&bp->tx_error_task);
+ break;
+ }
+
+ if (status & MACB_BIT(TCOMP))
+ macb_tx_interrupt(bp);
/*
* Link change detection isn't possible with RMII, so we'll
macb_writel(bp, NCR, MACB_BIT(RE) | MACB_BIT(TE) | MACB_BIT(MPE));
/* Enable interrupts */
- macb_writel(bp, IER, (MACB_BIT(RCOMP)
- | MACB_BIT(RXUBR)
- | MACB_BIT(ISR_TUND)
- | MACB_BIT(ISR_RLE)
- | MACB_BIT(TXERR)
- | MACB_BIT(TCOMP)
- | MACB_BIT(ISR_ROVR)
+ macb_writel(bp, IER, (MACB_RX_INT_FLAGS
+ | MACB_TX_INT_FLAGS
| MACB_BIT(HRESP)));
}
bp->dev = dev;
spin_lock_init(&bp->lock);
+ INIT_WORK(&bp->tx_error_task, macb_tx_error_task);
bp->pclk = clk_get(&pdev->dev, "pclk");
if (IS_ERR(bp->pclk)) {