nfp: update the old flash error message

Apparently there are still cards in the wild with a very old
management FW.  Let's make the error message in that case
indicate more clearly that management firmware has to be
updated.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NDirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c

@@ -241,11 +241,16 @@ static int nfp_nsp_check(struct nfp_nsp *state)
 	state->ver.major = FIELD_GET(NSP_STATUS_MAJOR, reg);
 	state->ver.minor = FIELD_GET(NSP_STATUS_MINOR, reg);
 
-	if (state->ver.major != NSP_MAJOR || state->ver.minor < NSP_MINOR) {
+	if (state->ver.major != NSP_MAJOR) {
 		nfp_err(cpp, "Unsupported ABI %hu.%hu\n",
 			state->ver.major, state->ver.minor);
 		return -EINVAL;
 	}
+	if (state->ver.minor < NSP_MINOR) {
+		nfp_err(cpp, "ABI too old to support NIC operation (%u.%hu < %u.%u), please update the management FW on the flash\n",
+			NSP_MAJOR, state->ver.minor, NSP_MAJOR, NSP_MINOR);
+		return -EINVAL;
+	}
 
 	if (reg & NSP_STATUS_BUSY) {
 		nfp_err(cpp, "Service processor busy!\n");