1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c
index 0dc800b5a4ea..a3c2aab53de8 100644
--- a/drivers/net/sfc/efx.c
+++ b/drivers/net/sfc/efx.c
@@ -328,7 +328,8 @@ static int efx_poll(struct napi_struct *napi, int budget)
  * processing to finish, then directly poll (and ack ) the eventq.
  * Finally reenable NAPI and interrupts.
  *
- * Since we are touching interrupts the caller should hold the suspend lock
+ * This is for use only during a loopback self-test.  It must not
+ * deliver any packets up the stack as this can result in deadlock.
  */
 void efx_process_channel_now(struct efx_channel *channel)
 {
@@ -336,6 +337,7 @@ void efx_process_channel_now(struct efx_channel *channel)
 
         BUG_ON(channel->channel >= efx->n_channels);
         BUG_ON(!channel->enabled);
+        BUG_ON(!efx->loopback_selftest);
 
         /* Disable interrupts and wait for ISRs to complete */
         efx_nic_disable_interrupts(efx);