[PATCH net-next] cxgb4: don't hold RTNL during ethtool phys_id

[Stephen Hemminger <shemminger@linux-foundation.org>]

The Chelsio cxgb4 drivers implement blinking in a unique way by
waiting on the mailbox. This patch cleans it up slightly by no longer
holding the system wide network configuration lock during the process.

The patch also uses correct semantics for the time argument
which is supposed to be in seconds; and zero is supposed
to signify infinite blinking.

This is still a bad firmware interface design for this
since it means the board is basically hung while doing the blink.
But fixing it correctly would require hardware and firmware
documentation. With that information the device could be converted
to the new set_phys_id.

Compile tested only.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

---
 drivers/net/cxgb4/cxgb4_main.c     |   17 ++++++++++++++---
 drivers/net/cxgb4vf/cxgb4vf_main.c |   21 +++++++++++++++++++--
 2 files changed, 33 insertions(+), 5 deletions(-)

--- a/drivers/net/cxgb4/cxgb4_main.c	2011-04-06 16:49:02.045648800 -0700
+++ b/drivers/net/cxgb4/cxgb4_main.c	2011-04-06 17:00:59.508851692 -0700
@@ -1339,12 +1339,23 @@ static int restart_autoneg(struct net_de
 static int identify_port(struct net_device *dev, u32 data)
 {
 	struct adapter *adap = netdev2adap(dev);
+	int rc;
+	unsigned long blinks;
 
 	if (data == 0)
-		data = 2;     /* default to 2 seconds */
+		blinks = UINT_MAX;
+	else
+		blinks = 2*data + data/2;
 
-	return t4_identify_port(adap, adap->fn, netdev2pinfo(dev)->viid,
-				data * 5);
+	/* Don't block networking updates while blink is in progress */
+	dev_hold(dev);
+	rtnl_unlock();
+
+	rc = t4_identify_port(adap, adap->fn, netdev2pinfo(dev)->viid,
+			      blinks);
+	rtnl_lock();
+	dev_put(dev);
+	return rc;
 }
 
 static unsigned int from_fw_linkcaps(unsigned int type, unsigned int caps)
--- a/drivers/net/cxgb4vf/cxgb4vf_main.c	2011-04-06 16:49:09.989728600 -0700
+++ b/drivers/net/cxgb4vf/cxgb4vf_main.c	2011-04-06 17:02:38.609846223 -0700
@@ -43,6 +43,7 @@
 #include <linux/etherdevice.h>
 #include <linux/debugfs.h>
 #include <linux/ethtool.h>
+#include <linux/rtnetlink.h>
 
 #include "t4vf_common.h"
 #include "t4vf_defs.h"
@@ -1352,11 +1353,27 @@ static int cxgb4vf_set_rx_csum(struct ne
 /*
  * Identify the port by blinking the port's LED.
  */
-static int cxgb4vf_phys_id(struct net_device *dev, u32 id)
+static int cxgb4vf_phys_id(struct net_device *dev, u32 data)
 {
 	struct port_info *pi = netdev_priv(dev);
+	int rc;
+	unsigned int blinks;
 
-	return t4vf_identify_port(pi->adapter, pi->viid, 5);
+	if (data == 0)
+		blinks = UINT_MAX;
+	else
+		blinks = 2*data + data/2;
+
+	/* Don't block networking updates while blink is in progress */
+	dev_hold(dev);
+	rtnl_unlock();
+
+	rc =  t4vf_identify_port(pi->adapter, pi->viid, blinks);
+
+	rtnl_lock();
+	dev_put(dev);
+
+	return rc;
 }
 
 /*