Re: [PATCH v3] net: macb: Handle HRESP error

From: Harini Katakam
Date: Sat Jan 27 2018 - 01:57:01 EST


Hi David,

On Sat, Jan 27, 2018 at 12:09 PM, <harinikatakamlinux@xxxxxxxxx> wrote:
> From: Harini Katakam <harini.katakam@xxxxxxxxxx>
>
> Handle HRESP error by doing a SW reset of RX and TX and
> re-initializing the descriptors, RX and TX queue pointers.
>
> Signed-off-by: Harini Katakam <harinik@xxxxxxxxxx>
> Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
> ---
> v3 and v2 changes:
> Fixed patch formatting errors
> Rebased on latest net-next and reinitialized
> multiple rx queues in error handling.
>
> drivers/net/ethernet/cadence/macb.h | 3 ++
> drivers/net/ethernet/cadence/macb_main.c | 59 +++++++++++++++++++++++++++++---
> 2 files changed, 58 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
> index c50c5ec..8665982 100644
> --- a/drivers/net/ethernet/cadence/macb.h
> +++ b/drivers/net/ethernet/cadence/macb.h
> @@ -13,6 +13,7 @@
> #include <linux/phy.h>
> #include <linux/ptp_clock_kernel.h>
> #include <linux/net_tstamp.h>
> +#include <linux/interrupt.h>
>
> #if defined(CONFIG_ARCH_DMA_ADDR_T_64BIT) || defined(CONFIG_MACB_USE_HWSTAMP)
> #define MACB_EXT_DESC
> @@ -1200,6 +1201,8 @@ struct macb {
> struct ethtool_rx_fs_list rx_fs_list;
> spinlock_t rx_fs_lock;
> unsigned int max_tuples;
> +
> + struct tasklet_struct hresp_err_tasklet;
> };
>
> #ifdef CONFIG_MACB_USE_HWSTAMP
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index 234667e..e84afcf 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -1258,6 +1258,57 @@ static int macb_poll(struct napi_struct *napi, int budget)
> return work_done;
> }
>
> +static void macb_hresp_error_task(unsigned long data)
> +{
> + struct macb *bp = (struct macb *)data;
> + struct net_device *dev = bp->dev;
> + struct macb_queue *queue = bp->queues;
> + unsigned int q;
> + u32 ctrl;
> +
> + for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
> + queue_writel(queue, IDR, MACB_RX_INT_FLAGS |
> + MACB_TX_INT_FLAGS |
> + MACB_BIT(HRESP));
> + }
> + ctrl = macb_readl(bp, NCR);
> + ctrl &= ~(MACB_BIT(RE) | MACB_BIT(TE));
> + macb_writel(bp, NCR, ctrl);
> +
> + netif_tx_stop_all_queues(dev);
> + netif_carrier_off(dev);
> +
> + bp->macbgem_ops.mog_init_rings(bp);
> +
> + /* Initialize TX and RX buffers */
> + for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
> + queue_writel(queue, RBQP, lower_32_bits(queue->rx_ring_dma));
> +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
> + if (bp->hw_dma_cap & HW_DMA_CAP_64B)
> + queue_writel(queue, RBQPH,
> + upper_32_bits(queue->rx_ring_dma));
> +#endif
> + queue_writel(queue, TBQP, lower_32_bits(queue->tx_ring_dma));
> +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
> + if (bp->hw_dma_cap & HW_DMA_CAP_64B)
> + queue_writel(queue, TBQPH,
> + upper_32_bits(queue->tx_ring_dma));
> +#endif
> +
> + /* Enable interrupts */
> + queue_writel(queue, IER,
> + MACB_RX_INT_FLAGS |
> + MACB_TX_INT_FLAGS |
> + MACB_BIT(HRESP));
> + }
> +
> + ctrl |= MACB_BIT(RE) | MACB_BIT(TE);
> + macb_writel(bp, NCR, ctrl);
> +
> + netif_carrier_on(dev);
> + netif_tx_start_all_queues(dev);
> +}
> +
> static irqreturn_t macb_interrupt(int irq, void *dev_id)
> {
> struct macb_queue *queue = dev_id;
> @@ -1347,10 +1398,7 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id)
> }
>
> if (status & MACB_BIT(HRESP)) {
> - /* TODO: Reset the hardware, and maybe move the
> - * netdev_err to a lower-priority context as well
> - * (work queue?)
> - */
> + tasklet_schedule(&bp->hresp_err_tasklet);
> netdev_err(dev, "DMA bus error: HRESP not OK\n");
>
> if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
> @@ -3937,6 +3985,9 @@ static int macb_probe(struct platform_device *pdev)
> goto err_out_unregister_mdio;
> }
>
> + tasklet_init(&bp->hresp_err_tasklet, macb_hresp_error_task,
> + (unsigned long)bp);
> +
> phy_attached_info(phydev);
>
> netdev_info(dev, "Cadence %s rev 0x%08x at 0x%08lx irq %d (%pM)\n",
> --
> 2.7.4
>

Apologies for the spam.
This is the v3. Please do let me know in case you still see any corruption.

Regards,
Harini