selftest.c

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/****************************************************************************
 * Driver for Solarflare Solarstorm network controllers and boards
 * Copyright 2005-2006 Fen Systems Ltd.
 * Copyright 2006-2010 Solarflare Communications Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation, incorporated herein by reference.
 */

#include <linux/netdevice.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/kernel_stat.h>
#include <linux/pci.h>
#include <linux/ethtool.h>
#include <linux/ip.h>
#include <linux/in.h>
#include <linux/udp.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include "net_driver.h"
#include "efx.h"
#include "nic.h"
#include "selftest.h"
#include "workarounds.h"

/* IRQ latency can be enormous because:
 * - All IRQs may be disabled on a CPU for a *long* time by e.g. a
 *   slow serial console or an old IDE driver doing error recovery
 * - The PREEMPT_RT patches mostly deal with this, but also allow a
 *   tasklet or normal task to be given higher priority than our IRQ
 *   threads
 * Try to avoid blaming the hardware for this.
 */
#define IRQ_TIMEOUT HZ

/*
 * Loopback test packet structure
 *
 * The self-test should stress every RSS vector, and unfortunately
 * Falcon only performs RSS on TCP/UDP packets.
 */
struct efx_loopback_payload {
    struct ethhdr header;
    struct iphdr ip;
    struct udphdr udp;
    __be16 iteration;
    const char msg[64];
} __packed;

/* Loopback test source MAC address */
static const unsigned char payload_source[ETH_ALEN] = {
    0x00, 0x0f, 0x53, 0x1b, 0x1b, 0x1b,
};

static const char payload_msg[] =
    "Hello world! This is an Efx loopback test in progress!";

/* Interrupt mode names */
static const unsigned int efx_interrupt_mode_max = EFX_INT_MODE_MAX;
static const char *const efx_interrupt_mode_names[] = {
    [EFX_INT_MODE_MSIX]   = "MSI-X",
    [EFX_INT_MODE_MSI]    = "MSI",
    [EFX_INT_MODE_LEGACY] = "legacy",
};
#define INT_MODE(efx) \
    STRING_TABLE_LOOKUP(efx->interrupt_mode, efx_interrupt_mode)

struct efx_loopback_state {
    bool flush;
    int packet_count;
    struct sk_buff **skbs;
    bool offload_csum;
    atomic_t rx_good;
    atomic_t rx_bad;
    struct efx_loopback_payload payload;
};

/* How long to wait for all the packets to arrive (in ms) */
#define LOOPBACK_TIMEOUT_MS 1000

/**************************************************************************
 *
 * MII, NVRAM and register tests
 *
 **************************************************************************/

static int efx_test_phy_alive(struct efx_nic *efx, struct efx_self_tests *tests)
{
    int rc = 0;

    if (efx->phy_op->test_alive) {
        rc = efx->phy_op->test_alive(efx);
        tests->phy_alive = rc ? -1 : 1;
    }

    return rc;
}

static int efx_test_nvram(struct efx_nic *efx, struct efx_self_tests *tests)
{
    int rc = 0;

    if (efx->type->test_nvram) {
        rc = efx->type->test_nvram(efx);
        tests->nvram = rc ? -1 : 1;
    }

    return rc;
}

/**************************************************************************
 *
 * Interrupt and event queue testing
 *
 **************************************************************************/

/* Test generation and receipt of interrupts */
static int efx_test_interrupts(struct efx_nic *efx,
                   struct efx_self_tests *tests)
{
    unsigned long timeout, wait;
    int cpu;

    netif_dbg(efx, drv, efx->net_dev, "testing interrupts\n");
    tests->interrupt = -1;

    efx_nic_irq_test_start(efx);
    timeout = jiffies + IRQ_TIMEOUT;
    wait = 1;

    /* Wait for arrival of test interrupt. */
    netif_dbg(efx, drv, efx->net_dev, "waiting for test interrupt\n");
    do {
        schedule_timeout_uninterruptible(wait);
        cpu = efx_nic_irq_test_irq_cpu(efx);
        if (cpu >= 0)
            goto success;
        wait *= 2;
    } while (time_before(jiffies, timeout));

    netif_err(efx, drv, efx->net_dev, "timed out waiting for interrupt\n");
    return -ETIMEDOUT;

 success:
    netif_dbg(efx, drv, efx->net_dev, "%s test interrupt seen on CPU%d\n",
          INT_MODE(efx), cpu);
    tests->interrupt = 1;
    return 0;
}

/* Test generation and receipt of interrupting events */
static int efx_test_eventq_irq(struct efx_nic *efx,
                   struct efx_self_tests *tests)
{
    struct efx_channel *channel;
    unsigned int read_ptr[EFX_MAX_CHANNELS];
    unsigned long napi_ran = 0, dma_pend = 0, int_pend = 0;
    unsigned long timeout, wait;

    BUILD_BUG_ON(EFX_MAX_CHANNELS > BITS_PER_LONG);

    efx_for_each_channel(channel, efx) {
        read_ptr[channel->channel] = channel->eventq_read_ptr;
        set_bit(channel->channel, &dma_pend);
        set_bit(channel->channel, &int_pend);
        efx_nic_event_test_start(channel);
    }

    timeout = jiffies + IRQ_TIMEOUT;
    wait = 1;

    /* Wait for arrival of interrupts.  NAPI processing may or may
     * not complete in time, but we can cope in any case.
     */
    do {
        schedule_timeout_uninterruptible(wait);

        efx_for_each_channel(channel, efx) {
            napi_disable(&channel->napi_str);
            if (channel->eventq_read_ptr !=
                read_ptr[channel->channel]) {
                set_bit(channel->channel, &napi_ran);
                clear_bit(channel->channel, &dma_pend);
                clear_bit(channel->channel, &int_pend);
            } else {
                if (efx_nic_event_present(channel))
                    clear_bit(channel->channel, &dma_pend);
                if (efx_nic_event_test_irq_cpu(channel) >= 0)
                    clear_bit(channel->channel, &int_pend);
            }
            napi_enable(&channel->napi_str);
            efx_nic_eventq_read_ack(channel);
        }

        wait *= 2;
    } while ((dma_pend || int_pend) && time_before(jiffies, timeout));

    efx_for_each_channel(channel, efx) {
        bool dma_seen = !test_bit(channel->channel, &dma_pend);
        bool int_seen = !test_bit(channel->channel, &int_pend);

        tests->eventq_dma[channel->channel] = dma_seen ? 1 : -1;
        tests->eventq_int[channel->channel] = int_seen ? 1 : -1;

        if (dma_seen && int_seen) {
            netif_dbg(efx, drv, efx->net_dev,
                  "channel %d event queue passed (with%s NAPI)\n",
                  channel->channel,
                  test_bit(channel->channel, &napi_ran) ?
                  "" : "out");
        } else {
            /* Report failure and whether either interrupt or DMA
             * worked
             */
            netif_err(efx, drv, efx->net_dev,
                  "channel %d timed out waiting for event queue\n",
                  channel->channel);
            if (int_seen)
                netif_err(efx, drv, efx->net_dev,
                      "channel %d saw interrupt "
                      "during event queue test\n",
                      channel->channel);
            if (dma_seen)
                netif_err(efx, drv, efx->net_dev,
                      "channel %d event was generated, but "
                      "failed to trigger an interrupt\n",
                      channel->channel);
        }
    }

    return (dma_pend || int_pend) ? -ETIMEDOUT : 0;
}

static int efx_test_phy(struct efx_nic *efx, struct efx_self_tests *tests,
            unsigned flags)
{
    int rc;

    if (!efx->phy_op->run_tests)
        return 0;

    mutex_lock(&efx->mac_lock);
    rc = efx->phy_op->run_tests(efx, tests->phy_ext, flags);
    mutex_unlock(&efx->mac_lock);
    return rc;
}

/**************************************************************************
 *
 * Loopback testing
 * NB Only one loopback test can be executing concurrently.
 *
 **************************************************************************/

/* Loopback test RX callback
 * This is called for each received packet during loopback testing.
 */
void efx_loopback_rx_packet(struct efx_nic *efx,
                const char *buf_ptr, int pkt_len)
{
    struct efx_loopback_state *state = efx->loopback_selftest;
    struct efx_loopback_payload *received;
    struct efx_loopback_payload *payload;

    BUG_ON(!buf_ptr);

    /* If we are just flushing, then drop the packet */
    if ((state == NULL) || state->flush)
        return;

    payload = &state->payload;

    received = (struct efx_loopback_payload *) buf_ptr;
    received->ip.saddr = payload->ip.saddr;
    if (state->offload_csum)
        received->ip.check = payload->ip.check;

    /* Check that header exists */
    if (pkt_len < sizeof(received->header)) {
        netif_err(efx, drv, efx->net_dev,
              "saw runt RX packet (length %d) in %s loopback "
              "test\n", pkt_len, LOOPBACK_MODE(efx));
        goto err;
    }

    /* Check that the ethernet header exists */
    if (memcmp(&received->header, &payload->header, ETH_HLEN) != 0) {
        netif_err(efx, drv, efx->net_dev,
              "saw non-loopback RX packet in %s loopback test\n",
              LOOPBACK_MODE(efx));
        goto err;
    }

    /* Check packet length */
    if (pkt_len != sizeof(*payload)) {
        netif_err(efx, drv, efx->net_dev,
              "saw incorrect RX packet length %d (wanted %d) in "
              "%s loopback test\n", pkt_len, (int)sizeof(*payload),
              LOOPBACK_MODE(efx));
        goto err;
    }

    /* Check that IP header matches */
    if (memcmp(&received->ip, &payload->ip, sizeof(payload->ip)) != 0) {
        netif_err(efx, drv, efx->net_dev,
              "saw corrupted IP header in %s loopback test\n",
              LOOPBACK_MODE(efx));
        goto err;
    }

    /* Check that msg and padding matches */
    if (memcmp(&received->msg, &payload->msg, sizeof(received->msg)) != 0) {
        netif_err(efx, drv, efx->net_dev,
              "saw corrupted RX packet in %s loopback test\n",
              LOOPBACK_MODE(efx));
        goto err;
    }

    /* Check that iteration matches */
    if (received->iteration != payload->iteration) {
        netif_err(efx, drv, efx->net_dev,
              "saw RX packet from iteration %d (wanted %d) in "
              "%s loopback test\n", ntohs(received->iteration),
              ntohs(payload->iteration), LOOPBACK_MODE(efx));
        goto err;
    }

    /* Increase correct RX count */
    netif_vdbg(efx, drv, efx->net_dev,
           "got loopback RX in %s loopback test\n", LOOPBACK_MODE(efx));

    atomic_inc(&state->rx_good);
    return;

 err:
#ifdef DEBUG
    if (atomic_read(&state->rx_bad) == 0) {
        netif_err(efx, drv, efx->net_dev, "received packet:\n");
        print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 0x10, 1,
                   buf_ptr, pkt_len, 0);
        netif_err(efx, drv, efx->net_dev, "expected packet:\n");
        print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 0x10, 1,
                   &state->payload, sizeof(state->payload), 0);
    }
#endif
    atomic_inc(&state->rx_bad);
}

/* Initialise an efx_selftest_state for a new iteration */
static void efx_iterate_state(struct efx_nic *efx)
{
    struct efx_loopback_state *state = efx->loopback_selftest;
    struct net_device *net_dev = efx->net_dev;
    struct efx_loopback_payload *payload = &state->payload;

    /* Initialise the layerII header */
    memcpy(&payload->header.h_dest, net_dev->dev_addr, ETH_ALEN);
    memcpy(&payload->header.h_source, &payload_source, ETH_ALEN);
    payload->header.h_proto = htons(ETH_P_IP);

    /* saddr set later and used as incrementing count */
    payload->ip.daddr = htonl(INADDR_LOOPBACK);
    payload->ip.ihl = 5;
    payload->ip.check = htons(0xdead);
    payload->ip.tot_len = htons(sizeof(*payload) - sizeof(struct ethhdr));
    payload->ip.version = IPVERSION;
    payload->ip.protocol = IPPROTO_UDP;

    /* Initialise udp header */
    payload->udp.source = 0;
    payload->udp.len = htons(sizeof(*payload) - sizeof(struct ethhdr) -
                 sizeof(struct iphdr));
    payload->udp.check = 0; /* checksum ignored */

    /* Fill out payload */
    payload->iteration = htons(ntohs(payload->iteration) + 1);
    memcpy(&payload->msg, payload_msg, sizeof(payload_msg));

    /* Fill out remaining state members */
    atomic_set(&state->rx_good, 0);
    atomic_set(&state->rx_bad, 0);
    smp_wmb();
}

static int efx_begin_loopback(struct efx_tx_queue *tx_queue)
{
    struct efx_nic *efx = tx_queue->efx;
    struct efx_loopback_state *state = efx->loopback_selftest;
    struct efx_loopback_payload *payload;
    struct sk_buff *skb;
    int i;
    netdev_tx_t rc;

    /* Transmit N copies of buffer */
    for (i = 0; i < state->packet_count; i++) {
        /* Allocate an skb, holding an extra reference for
         * transmit completion counting */
        skb = alloc_skb(sizeof(state->payload), GFP_KERNEL);
        if (!skb)
            return -ENOMEM;
        state->skbs[i] = skb;
        skb_get(skb);

        /* Copy the payload in, incrementing the source address to
         * exercise the rss vectors */
        payload = ((struct efx_loopback_payload *)
               skb_put(skb, sizeof(state->payload)));
        memcpy(payload, &state->payload, sizeof(state->payload));
        payload->ip.saddr = htonl(INADDR_LOOPBACK | (i << 2));

        /* Ensure everything we've written is visible to the
         * interrupt handler. */
        smp_wmb();

        netif_tx_lock_bh(efx->net_dev);
        rc = efx_enqueue_skb(tx_queue, skb);
        netif_tx_unlock_bh(efx->net_dev);

        if (rc != NETDEV_TX_OK) {
            netif_err(efx, drv, efx->net_dev,
                  "TX queue %d could not transmit packet %d of "
                  "%d in %s loopback test\n", tx_queue->queue,
                  i + 1, state->packet_count,
                  LOOPBACK_MODE(efx));

            /* Defer cleaning up the other skbs for the caller */
            kfree_skb(skb);
            return -EPIPE;
        }
    }

    return 0;
}

static int efx_poll_loopback(struct efx_nic *efx)
{
    struct efx_loopback_state *state = efx->loopback_selftest;
    struct efx_channel *channel;

    /* NAPI polling is not enabled, so process channels
     * synchronously */
    efx_for_each_channel(channel, efx) {
        if (channel->work_pending)
            efx_process_channel_now(channel);
    }
    return atomic_read(&state->rx_good) == state->packet_count;
}

static int efx_end_loopback(struct efx_tx_queue *tx_queue,
                struct efx_loopback_self_tests *lb_tests)
{
    struct efx_nic *efx = tx_queue->efx;
    struct efx_loopback_state *state = efx->loopback_selftest;
    struct sk_buff *skb;
    int tx_done = 0, rx_good, rx_bad;
    int i, rc = 0;

    netif_tx_lock_bh(efx->net_dev);

    /* Count the number of tx completions, and decrement the refcnt. Any
     * skbs not already completed will be free'd when the queue is flushed */
    for (i = 0; i < state->packet_count; i++) {
        skb = state->skbs[i];
        if (skb && !skb_shared(skb))
            ++tx_done;
        dev_kfree_skb(skb);
    }

    netif_tx_unlock_bh(efx->net_dev);

    /* Check TX completion and received packet counts */
    rx_good = atomic_read(&state->rx_good);
    rx_bad = atomic_read(&state->rx_bad);
    if (tx_done != state->packet_count) {
        /* Don't free the skbs; they will be picked up on TX
         * overflow or channel teardown.
         */
        netif_err(efx, drv, efx->net_dev,
              "TX queue %d saw only %d out of an expected %d "
              "TX completion events in %s loopback test\n",
              tx_queue->queue, tx_done, state->packet_count,
              LOOPBACK_MODE(efx));
        rc = -ETIMEDOUT;
        /* Allow to fall through so we see the RX errors as well */
    }

    /* We may always be up to a flush away from our desired packet total */
    if (rx_good != state->packet_count) {
        netif_dbg(efx, drv, efx->net_dev,
              "TX queue %d saw only %d out of an expected %d "
              "received packets in %s loopback test\n",
              tx_queue->queue, rx_good, state->packet_count,
              LOOPBACK_MODE(efx));
        rc = -ETIMEDOUT;
        /* Fall through */
    }

    /* Update loopback test structure */
    lb_tests->tx_sent[tx_queue->queue] += state->packet_count;
    lb_tests->tx_done[tx_queue->queue] += tx_done;
    lb_tests->rx_good += rx_good;
    lb_tests->rx_bad += rx_bad;

    return rc;
}

static int
efx_test_loopback(struct efx_tx_queue *tx_queue,
          struct efx_loopback_self_tests *lb_tests)
{
    struct efx_nic *efx = tx_queue->efx;
    struct efx_loopback_state *state = efx->loopback_selftest;
    int i, begin_rc, end_rc;

    for (i = 0; i < 3; i++) {
        /* Determine how many packets to send */
        state->packet_count = efx->txq_entries / 3;
        state->packet_count = min(1 << (i << 2), state->packet_count);
        state->skbs = kcalloc(state->packet_count,
                      sizeof(state->skbs[0]), GFP_KERNEL);
        if (!state->skbs)
            return -ENOMEM;
        state->flush = false;

        netif_dbg(efx, drv, efx->net_dev,
              "TX queue %d testing %s loopback with %d packets\n",
              tx_queue->queue, LOOPBACK_MODE(efx),
              state->packet_count);

        efx_iterate_state(efx);
        begin_rc = efx_begin_loopback(tx_queue);

        /* This will normally complete very quickly, but be
         * prepared to wait much longer. */
        msleep(1);
        if (!efx_poll_loopback(efx)) {
            msleep(LOOPBACK_TIMEOUT_MS);
            efx_poll_loopback(efx);
        }

        end_rc = efx_end_loopback(tx_queue, lb_tests);
        kfree(state->skbs);

        if (begin_rc || end_rc) {
            /* Wait a while to ensure there are no packets
             * floating around after a failure. */
            schedule_timeout_uninterruptible(HZ / 10);
            return begin_rc ? begin_rc : end_rc;
        }
    }

    netif_dbg(efx, drv, efx->net_dev,
          "TX queue %d passed %s loopback test with a burst length "
          "of %d packets\n", tx_queue->queue, LOOPBACK_MODE(efx),
          state->packet_count);

    return 0;
}

/* Wait for link up. On Falcon, we would prefer to rely on efx_monitor, but
 * any contention on the mac lock (via e.g. efx_mac_mcast_work) causes it
 * to delay and retry. Therefore, it's safer to just poll directly. Wait
 * for link up and any faults to dissipate. */
static int efx_wait_for_link(struct efx_nic *efx)
{
    struct efx_link_state *link_state = &efx->link_state;
    int count, link_up_count = 0;
    bool link_up;

    for (count = 0; count < 40; count++) {
        schedule_timeout_uninterruptible(HZ / 10);

        if (efx->type->monitor != NULL) {
            mutex_lock(&efx->mac_lock);
            efx->type->monitor(efx);
            mutex_unlock(&efx->mac_lock);
        } else {
            struct efx_channel *channel = efx_get_channel(efx, 0);
            if (channel->work_pending)
                efx_process_channel_now(channel);
        }

        mutex_lock(&efx->mac_lock);
        link_up = link_state->up;
        if (link_up)
            link_up = !efx->type->check_mac_fault(efx);
        mutex_unlock(&efx->mac_lock);

        if (link_up) {
            if (++link_up_count == 2)
                return 0;
        } else {
            link_up_count = 0;
        }
    }

    return -ETIMEDOUT;
}

static int efx_test_loopbacks(struct efx_nic *efx, struct efx_self_tests *tests,
                  unsigned int loopback_modes)
{
    enum efx_loopback_mode mode;
    struct efx_loopback_state *state;
    struct efx_channel *channel =
        efx_get_channel(efx, efx->tx_channel_offset);
    struct efx_tx_queue *tx_queue;
    int rc = 0;

    /* Set the port loopback_selftest member. From this point on
     * all received packets will be dropped. Mark the state as
     * "flushing" so all inflight packets are dropped */
    state = kzalloc(sizeof(*state), GFP_KERNEL);
    if (state == NULL)
        return -ENOMEM;
    BUG_ON(efx->loopback_selftest);
    state->flush = true;
    efx->loopback_selftest = state;

    /* Test all supported loopback modes */
    for (mode = LOOPBACK_NONE; mode <= LOOPBACK_TEST_MAX; mode++) {
        if (!(loopback_modes & (1 << mode)))
            continue;

        /* Move the port into the specified loopback mode. */
        state->flush = true;
        mutex_lock(&efx->mac_lock);
        efx->loopback_mode = mode;
        rc = __efx_reconfigure_port(efx);
        mutex_unlock(&efx->mac_lock);
        if (rc) {
            netif_err(efx, drv, efx->net_dev,
                  "unable to move into %s loopback\n",
                  LOOPBACK_MODE(efx));
            goto out;
        }

        rc = efx_wait_for_link(efx);
        if (rc) {
            netif_err(efx, drv, efx->net_dev,
                  "loopback %s never came up\n",
                  LOOPBACK_MODE(efx));
            goto out;
        }

        /* Test all enabled types of TX queue */
        efx_for_each_channel_tx_queue(tx_queue, channel) {
            state->offload_csum = (tx_queue->queue &
                           EFX_TXQ_TYPE_OFFLOAD);
            rc = efx_test_loopback(tx_queue,
                           &tests->loopback[mode]);
            if (rc)
                goto out;
        }
    }

 out:
    /* Remove the flush. The caller will remove the loopback setting */
    state->flush = true;
    efx->loopback_selftest = NULL;
    wmb();
    kfree(state);

    return rc;
}

/**************************************************************************
 *
 * Entry point
 *
 *************************************************************************/

int efx_selftest(struct efx_nic *efx, struct efx_self_tests *tests,
         unsigned flags)
{
    enum efx_loopback_mode loopback_mode = efx->loopback_mode;
    int phy_mode = efx->phy_mode;
    int rc_test = 0, rc_reset, rc;

    efx_selftest_async_cancel(efx);

    /* Online (i.e. non-disruptive) testing
     * This checks interrupt generation, event delivery and PHY presence. */

    rc = efx_test_phy_alive(efx, tests);
    if (rc && !rc_test)
        rc_test = rc;

    rc = efx_test_nvram(efx, tests);
    if (rc && !rc_test)
        rc_test = rc;

    rc = efx_test_interrupts(efx, tests);
    if (rc && !rc_test)
        rc_test = rc;

    rc = efx_test_eventq_irq(efx, tests);
    if (rc && !rc_test)
        rc_test = rc;

    if (rc_test)
        return rc_test;

    if (!(flags & ETH_TEST_FL_OFFLINE))
        return efx_test_phy(efx, tests, flags);

    /* Offline (i.e. disruptive) testing
     * This checks MAC and PHY loopback on the specified port. */

    /* Detach the device so the kernel doesn't transmit during the
     * loopback test and the watchdog timeout doesn't fire.
     */
    netif_device_detach(efx->net_dev);

    if (efx->type->test_chip) {
        rc_reset = efx->type->test_chip(efx, tests);
        if (rc_reset) {
            netif_err(efx, hw, efx->net_dev,
                  "Unable to recover from chip test\n");
            efx_schedule_reset(efx, RESET_TYPE_DISABLE);
            return rc_reset;
        }

        if ((tests->registers < 0) && !rc_test)
            rc_test = -EIO;
    }

    /* Ensure that the phy is powered and out of loopback
     * for the bist and loopback tests */
    mutex_lock(&efx->mac_lock);
    efx->phy_mode &= ~PHY_MODE_LOW_POWER;
    efx->loopback_mode = LOOPBACK_NONE;
    __efx_reconfigure_port(efx);
    mutex_unlock(&efx->mac_lock);

    rc = efx_test_phy(efx, tests, flags);
    if (rc && !rc_test)
        rc_test = rc;

    rc = efx_test_loopbacks(efx, tests, efx->loopback_modes);
    if (rc && !rc_test)
        rc_test = rc;

    /* restore the PHY to the previous state */
    mutex_lock(&efx->mac_lock);
    efx->phy_mode = phy_mode;
    efx->loopback_mode = loopback_mode;
    __efx_reconfigure_port(efx);
    mutex_unlock(&efx->mac_lock);

    netif_device_attach(efx->net_dev);

    return rc_test;
}

void efx_selftest_async_start(struct efx_nic *efx)
{
    struct efx_channel *channel;

    efx_for_each_channel(channel, efx)
        efx_nic_event_test_start(channel);
    schedule_delayed_work(&efx->selftest_work, IRQ_TIMEOUT);
}

void efx_selftest_async_cancel(struct efx_nic *efx)
{
    cancel_delayed_work_sync(&efx->selftest_work);
}

void efx_selftest_async_work(struct work_struct *data)
{
    struct efx_nic *efx = container_of(data, struct efx_nic,
                       selftest_work.work);
    struct efx_channel *channel;
    int cpu;

    efx_for_each_channel(channel, efx) {
        cpu = efx_nic_event_test_irq_cpu(channel);
        if (cpu < 0)
            netif_err(efx, ifup, efx->net_dev,
                  "channel %d failed to trigger an interrupt\n",
                  channel->channel);
        else
            netif_dbg(efx, ifup, efx->net_dev,
                  "channel %d triggered interrupt on CPU %d\n",
                  channel->channel, cpu);
    }
}