[Precise][PATCH 1/1] tg3: Fix TSO CAP for 5704 devs w / ASF enabled

[joseph.salisbury at canonical.com]

From: Matt Carlson <mcarlson at broadcom.com>

BugLink: http://bugs.launchpad.net/bugs/1005699

On the earliest TSO capable devices, TSO was accomplished through
firmware.  The TSO cannot coexist with ASF management firmware though.
The tg3 driver determines whether or not ASF is enabled by calling
tg3_get_eeprom_hw_cfg(), which checks a particular bit of NIC memory.
Commit dabc5c670d3f86d15ee4f42ab38ec5bd2682487d, entitled "tg3: Move
TSO_CAPABLE assignment", accidentally moved the code that determines
TSO capabilities earlier than the call to tg3_get_eeprom_hw_cfg().  As a
consequence, the driver was attempting to determine TSO capabilities
before it had all the data it needed to make the decision.

This patch fixes the problem by revisiting and reevaluating the decision
after tg3_get_eeprom_hw_cfg() is called.

Signed-off-by: Matt Carlson <mcarlson at broadcom.com>
Signed-off-by: Michael Chan <mchan at broadcom.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit cf9ecf4b631f649a964fa611f1a5e8874f2a76db)

Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
---
 drivers/net/ethernet/broadcom/tg3.c |   14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 7efa8de..0341e5f 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -14013,9 +14013,13 @@ static int __devinit tg3_get_invariants(struct tg3 *tp)
 	if (tg3_flag(tp, HW_TSO_1) ||
 	    tg3_flag(tp, HW_TSO_2) ||
 	    tg3_flag(tp, HW_TSO_3) ||
-	    (tp->fw_needed && !tg3_flag(tp, ENABLE_ASF)))
+	    tp->fw_needed) {
+		/* For firmware TSO, assume ASF is disabled.
+		 * We'll disable TSO later if we discover ASF
+		 * is enabled in tg3_get_eeprom_hw_cfg().
+		 */
 		tg3_flag_set(tp, TSO_CAPABLE);
-	else {
+	} else {
 		tg3_flag_clear(tp, TSO_CAPABLE);
 		tg3_flag_clear(tp, TSO_BUG);
 		tp->fw_needed = NULL;
@@ -14289,6 +14293,12 @@ static int __devinit tg3_get_invariants(struct tg3 *tp)
 	 */
 	tg3_get_eeprom_hw_cfg(tp);
 
+	if (tp->fw_needed && tg3_flag(tp, ENABLE_ASF)) {
+		tg3_flag_clear(tp, TSO_CAPABLE);
+		tg3_flag_clear(tp, TSO_BUG);
+		tp->fw_needed = NULL;
+	}
+
 	if (tg3_flag(tp, ENABLE_APE)) {
 		/* Allow reads and writes to the
 		 * APE register and memory space.
-- 
1.7.9.5