e1000e: clear REQ and GNT in EECD (82571 && 82572)
Clear the REQ and GNT bit in the eeprom control register (EECD).
This is required if the eeprom is to be accessed with auto read
EERD register.
After a cold reset this doesn't matter but if PBIST MAC test was
executed before booting, the register was left in a dirty state
(the 2 bits where set), which caused the read operation to time out
and returning 0.
Reference (page 312):
http://download.intel.com/design/network/manuals/316080.pdf
Reported-by: Aleksandar Igic <aleksandar.igic@dektech.com.au>
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/e1000e/82571.c b/drivers/net/ethernet/intel/e1000e/82571.c
index 6a8a908..36db4df 100644
--- a/drivers/net/ethernet/intel/e1000e/82571.c
+++ b/drivers/net/ethernet/intel/e1000e/82571.c
@@ -999,7 +999,7 @@
**/
static s32 e1000_reset_hw_82571(struct e1000_hw *hw)
{
- u32 ctrl, ctrl_ext;
+ u32 ctrl, ctrl_ext, eecd;
s32 ret_val;
/*
@@ -1072,6 +1072,16 @@
*/
switch (hw->mac.type) {
+ case e1000_82571:
+ case e1000_82572:
+ /*
+ * REQ and GNT bits need to be cleared when using AUTO_RD
+ * to access the EEPROM.
+ */
+ eecd = er32(EECD);
+ eecd &= ~(E1000_EECD_REQ | E1000_EECD_GNT);
+ ew32(EECD, eecd);
+ break;
case e1000_82573:
case e1000_82574:
case e1000_82583: