1 files changed, 46 insertions, 11 deletions

diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index c082562dbf4e..4b0bd8a1514d 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -50,6 +50,7 @@ struct efx_mcdi_async_param {
 static void efx_mcdi_timeout_async(unsigned long context);
 static int efx_mcdi_drv_attach(struct efx_nic *efx, bool driver_operating,
 			       bool *was_attached_out);
+static bool efx_mcdi_poll_once(struct efx_nic *efx);
 
 static inline struct efx_mcdi_iface *efx_mcdi(struct efx_nic *efx)
 {
@@ -237,6 +238,21 @@ static void efx_mcdi_read_response_header(struct efx_nic *efx)
 	}
 }
 
+static bool efx_mcdi_poll_once(struct efx_nic *efx)
+{
+	struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
+
+	rmb();
+	if (!efx->type->mcdi_poll_response(efx))
+		return false;
+
+	spin_lock_bh(&mcdi->iface_lock);
+	efx_mcdi_read_response_header(efx);
+	spin_unlock_bh(&mcdi->iface_lock);
+
+	return true;
+}
+
 static int efx_mcdi_poll(struct efx_nic *efx)
 {
 	struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
@@ -272,18 +288,13 @@ static int efx_mcdi_poll(struct efx_nic *efx)
 
 		time = jiffies;
 
-		rmb();
-		if (efx->type->mcdi_poll_response(efx))
+		if (efx_mcdi_poll_once(efx))
 			break;
 
 		if (time_after(time, finish))
 			return -ETIMEDOUT;
 	}
 
-	spin_lock_bh(&mcdi->iface_lock);
-	efx_mcdi_read_response_header(efx);
-	spin_unlock_bh(&mcdi->iface_lock);
-
 	/* Return rc=0 like wait_event_timeout() */
 	return 0;
 }
@@ -619,6 +630,16 @@ int efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
 		rc = efx_mcdi_await_completion(efx);
 
 	if (rc != 0) {
+		netif_err(efx, hw, efx->net_dev,
+			  "MC command 0x%x inlen %d mode %d timed out\n",
+			  cmd, (int)inlen, mcdi->mode);
+
+		if (mcdi->mode == MCDI_MODE_EVENTS && efx_mcdi_poll_once(efx)) {
+			netif_err(efx, hw, efx->net_dev,
+				  "MCDI request was completed without an event\n");
+			rc = 0;
+		}
+
 		/* Close the race with efx_mcdi_ev_cpl() executing just too late
 		 * and completing a request we've just cancelled, by ensuring
 		 * that the seqno check therein fails.
@@ -627,11 +648,9 @@ int efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
 		++mcdi->seqno;
 		++mcdi->credits;
 		spin_unlock_bh(&mcdi->iface_lock);
+	}
 
-		netif_err(efx, hw, efx->net_dev,
-			  "MC command 0x%x inlen %d mode %d timed out\n",
-			  cmd, (int)inlen, mcdi->mode);
-	} else {
+	if (rc == 0) {
 		size_t hdr_len, data_len;
 
 		/* At the very least we need a memory barrier here to ensure
@@ -963,7 +982,7 @@ static int efx_mcdi_drv_attach(struct efx_nic *efx, bool driver_operating,
 			       bool *was_attached)
 {
 	MCDI_DECLARE_BUF(inbuf, MC_CMD_DRV_ATTACH_IN_LEN);
-	MCDI_DECLARE_BUF(outbuf, MC_CMD_DRV_ATTACH_OUT_LEN);
+	MCDI_DECLARE_BUF(outbuf, MC_CMD_DRV_ATTACH_EXT_OUT_LEN);
 	size_t outlen;
 	int rc;
 
@@ -981,6 +1000,22 @@ static int efx_mcdi_drv_attach(struct efx_nic *efx, bool driver_operating,
 		goto fail;
 	}
 
+	/* We currently assume we have control of the external link
+	 * and are completely trusted by firmware.  Abort probing
+	 * if that's not true for this function.
+	 */
+	if (driver_operating &&
+	    outlen >= MC_CMD_DRV_ATTACH_EXT_OUT_LEN &&
+	    (MCDI_DWORD(outbuf, DRV_ATTACH_EXT_OUT_FUNC_FLAGS) &
+	     (1 << MC_CMD_DRV_ATTACH_EXT_OUT_FLAG_LINKCTRL |
+	      1 << MC_CMD_DRV_ATTACH_EXT_OUT_FLAG_TRUSTED)) !=
+	    (1 << MC_CMD_DRV_ATTACH_EXT_OUT_FLAG_LINKCTRL |
+	     1 << MC_CMD_DRV_ATTACH_EXT_OUT_FLAG_TRUSTED)) {
+		netif_err(efx, probe, efx->net_dev,
+			  "This driver version only supports one function per port\n");
+		return -ENODEV;
+	}
+
 	if (was_attached != NULL)
 		*was_attached = MCDI_DWORD(outbuf, DRV_ATTACH_OUT_OLD_STATE);
 	return 0;