sfc: Stop RX refill before flushing RX queues

rx_queue::enabled guards refill, so rename it to reflect that.  Clear
it at the start of the queue teardown process rather than waiting for
the RX queue to be flushed.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

4 files changed, 13 insertions, 9 deletions

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index a7818d1c2415..ee9242cf5fd7 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -248,8 +248,7 @@ static int efx_process_channel(struct efx_channel *channel, int budget)
                         efx_channel_get_rx_queue(channel);
 
                 efx_rx_flush_packet(channel);
-                if (rx_queue->enabled)
-                        efx_fast_push_rx_descriptors(rx_queue);
+                efx_fast_push_rx_descriptors(rx_queue);
         }
 
         return spent;
@@ -647,6 +646,12 @@ static void efx_stop_datapath(struct efx_nic *efx)
         EFX_ASSERT_RESET_SERIALISED(efx);
         BUG_ON(efx->port_enabled);
 
+        /* Stop RX refill */
+        efx_for_each_channel(channel, efx) {
+                efx_for_each_channel_rx_queue(rx_queue, channel)
+                        rx_queue->refill_enabled = false;
+        }
+
         /* Only perform flush if dma is enabled */
         if (dev->is_busmaster && efx->state != STATE_RECOVERY) {
                 rc = efx_nic_flush_queues(efx);
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 7c9637203ea0..c9f798913f39 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -286,7 +286,7 @@ struct efx_rx_page_state {
  * @buffer: The software buffer ring
  * @rxd: The hardware descriptor ring
  * @ptr_mask: The size of the ring minus 1.
- * @enabled: Receive queue enabled indicator.
+ * @refill_enabled: Enable refill whenever fill level is low
  * @flush_pending: Set when a RX flush is pending. Has the same lifetime as
  *      @rxq_flush_pending.
  * @added_count: Number of buffers added to the receive queue.
@@ -317,7 +317,7 @@ struct efx_rx_queue {
         struct efx_rx_buffer *buffer;
         struct efx_special_buffer rxd;
         unsigned int ptr_mask;
-        bool enabled;
+        bool refill_enabled;
         bool flush_pending;
 
         unsigned int added_count;
diff --git a/drivers/net/ethernet/sfc/nic.c b/drivers/net/ethernet/sfc/nic.c
index 2d0a584e1af2..deb0ee04fe70 100644
--- a/drivers/net/ethernet/sfc/nic.c
+++ b/drivers/net/ethernet/sfc/nic.c
@@ -1204,7 +1204,6 @@ efx_handle_generated_event(struct efx_channel *channel, efx_qword_t *event)
                  * queue. Refill it here */
                 efx_fast_push_rx_descriptors(rx_queue);
         } else if (rx_queue && magic == EFX_CHANNEL_MAGIC_RX_DRAIN(rx_queue)) {
-                rx_queue->enabled = false;
                 efx_handle_drain_event(channel);
         } else if (code == _EFX_CHANNEL_MAGIC_TX_DRAIN) {
                 efx_handle_drain_event(channel);
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index 6af9cfda50fb..8b482dee4eb0 100644
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -326,6 +326,9 @@ void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue)
         unsigned int fill_level, batch_size;
         int space, rc = 0;
 
+        if (!rx_queue->refill_enabled)
+                return;
+
         /* Calculate current fill level, and exit if we don't need to fill */
         fill_level = (rx_queue->added_count - rx_queue->removed_count);
         EFX_BUG_ON_PARANOID(fill_level > rx_queue->efx->rxq_entries);
@@ -738,9 +741,9 @@ void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
 
         rx_queue->max_fill = max_fill;
         rx_queue->fast_fill_trigger = trigger;
+        rx_queue->refill_enabled = true;
 
         /* Set up RX descriptor ring */
-        rx_queue->enabled = true;
         efx_nic_init_rx(rx_queue);
 }
 
@@ -753,9 +756,6 @@ void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
                   "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
 
-        /* A flush failure might have left rx_queue->enabled */
-        rx_queue->enabled = false;
-
         del_timer_sync(&rx_queue->slow_fill);
         efx_nic_fini_rx(rx_queue);