sfc: Speed up loopback self-test

Add efx_poll_loopback() function to test for successful completion of test.
Change efx_test_loopback() to end the test after 1 ms if
efx_poll_loopback() indicates success, and otherwise to wait for 100 ms
as before.

While we're here, rename efx_{rx,tx}_loopback() to
efx_{begin,end}_loopback() which more accurately reflect their
purpose.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 29 insertions, 15 deletions

diff --git a/drivers/net/sfc/selftest.c b/drivers/net/sfc/selftest.c
index 8ad517c61946..53fa4edf486c 100644
--- a/drivers/net/sfc/selftest.c
+++ b/drivers/net/sfc/selftest.c
@@ -400,7 +400,7 @@ static void efx_iterate_state(struct efx_nic *efx)
         smp_wmb();
 }
 
-static int efx_tx_loopback(struct efx_tx_queue *tx_queue)
+static int efx_begin_loopback(struct efx_tx_queue *tx_queue)
 {
         struct efx_nic *efx = tx_queue->efx;
         struct efx_selftest_state *state = efx->loopback_selftest;
@@ -449,8 +449,22 @@ static int efx_tx_loopback(struct efx_tx_queue *tx_queue)
         return 0;
 }
 
-static int efx_rx_loopback(struct efx_tx_queue *tx_queue,
-                           struct efx_loopback_self_tests *lb_tests)
+static int efx_poll_loopback(struct efx_nic *efx)
+{
+        struct efx_selftest_state *state = efx->loopback_selftest;
+        struct efx_channel *channel;
+
+        /* NAPI polling is not enabled, so process channels
+         * synchronously */
+        efx_for_each_channel_with_interrupt(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_selftest_state *state = efx->loopback_selftest;
@@ -513,8 +527,7 @@ efx_test_loopback(struct efx_tx_queue *tx_queue,
 {
         struct efx_nic *efx = tx_queue->efx;
         struct efx_selftest_state *state = efx->loopback_selftest;
-        struct efx_channel *channel;
-        int i, tx_rc, rx_rc;
+        int i, begin_rc, end_rc;
 
         for (i = 0; i < loopback_test_level; i++) {
                 /* Determine how many packets to send */
@@ -531,23 +544,24 @@ efx_test_loopback(struct efx_tx_queue *tx_queue,
                         state->packet_count);
 
                 efx_iterate_state(efx);
-                tx_rc = efx_tx_loopback(tx_queue);
-                
-                /* NAPI polling is not enabled, so process channels synchronously */
-                schedule_timeout_uninterruptible(HZ / 50);
-                efx_for_each_channel_with_interrupt(channel, efx) {
-                        if (channel->work_pending)
-                                efx_process_channel_now(channel);
+                begin_rc = efx_begin_loopback(tx_queue);
+
+                /* This will normally complete very quickly, but be
+                 * prepared to wait up to 100 ms. */
+                msleep(1);
+                if (!efx_poll_loopback(efx)) {
+                        msleep(100);
+                        efx_poll_loopback(efx);
                 }
 
-                rx_rc = efx_rx_loopback(tx_queue, lb_tests);
+                end_rc = efx_end_loopback(tx_queue, lb_tests);
                 kfree(state->skbs);
 
-                if (tx_rc || rx_rc) {
+                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 tx_rc ? tx_rc : rx_rc;
+                        return begin_rc ? begin_rc : end_rc;
                 }
         }