be2net: Warn users of possible broken functionality on BE2 cards with very old FW versions with latest driver

On very old FW versions < 4.0, the mailbox command to set interrupts
on the card succeeds even though it is not supported and should have
failed, leading to a scenario where interrupts do not work.
Hence warn users to upgrade to a suitable FW version to avoid seeing
broken functionality.

Signed-off-by: Somnath Kotur <somnath.kotur@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/emulex/benet/be.h

@@ -696,6 +696,15 @@ static inline int qnq_async_evt_rcvd(struct be_adapter *adapter)
 	return adapter->flags & BE_FLAGS_QNQ_ASYNC_EVT_RCVD;
 }
 
+static inline int fw_major_num(const char *fw_ver)
+{
+	int fw_major = 0;
+
+	sscanf(fw_ver, "%d.", &fw_major);
+
+	return fw_major;
+}
+
 extern void be_cq_notify(struct be_adapter *adapter, u16 qid, bool arm,
 		u16 num_popped);
 extern void be_link_status_update(struct be_adapter *adapter, u8 link_status);

drivers/net/ethernet/emulex/benet/be_main.c

@@ -3247,6 +3247,12 @@ static int be_setup(struct be_adapter *adapter)
 
 	be_cmd_get_fw_ver(adapter, adapter->fw_ver, adapter->fw_on_flash);
 
+	if (BE2_chip(adapter) && fw_major_num(adapter->fw_ver) < 4) {
+		dev_err(dev, "Firmware on card is old(%s), IRQs may not work.",
+			adapter->fw_ver);
+		dev_err(dev, "Please upgrade firmware to version >= 4.0\n");
+	}
+
 	if (adapter->vlans_added)
 		be_vid_config(adapter);