net: stmmac: dwmac1000: Also pass control frames while in promisc mode

In order for the selftests to run the Flow Control selftest we need to
also pass pause frames to the stack.

Pass this type of frames while in promiscuous mode.
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac1000.h

@@ -146,6 +146,7 @@ enum inter_frame_gap {
 #define GMAC_FRAME_FILTER_DAIF	0x00000008	/* DA Inverse Filtering */
 #define GMAC_FRAME_FILTER_PM	0x00000010	/* Pass all multicast */
 #define GMAC_FRAME_FILTER_DBF	0x00000020	/* Disable Broadcast frames */
+#define GMAC_FRAME_FILTER_PCF	0x00000080	/* Pass Control frames */
 #define GMAC_FRAME_FILTER_SAIF	0x00000100	/* Inverse Filtering */
 #define GMAC_FRAME_FILTER_SAF	0x00000200	/* Source Address Filter */
 #define GMAC_FRAME_FILTER_HPF	0x00000400	/* Hash or perfect Filter */

drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c

@@ -172,7 +172,7 @@ static void dwmac1000_set_filter(struct mac_device_info *hw,
 	memset(mc_filter, 0, sizeof(mc_filter));
 
 	if (dev->flags & IFF_PROMISC) {
-		value = GMAC_FRAME_FILTER_PR;
+		value = GMAC_FRAME_FILTER_PR | GMAC_FRAME_FILTER_PCF;
 	} else if (dev->flags & IFF_ALLMULTI) {
 		value = GMAC_FRAME_FILTER_PM;	/* pass all multi */
 	} else if (!netdev_mc_empty(dev)) {