From: Greg KH <[email protected]>

3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tushar Dave <[email protected]>

commit d0efa8f23a644f7cb7d1f8e78dd9a223efa412a3 upstream.

SYNCH bit and IV bit of RXCW register are sticky. Before examining these bits,
RXCW should be read twice to filter out one-time false events and have correct
values for these bits. Incorrect values of these bits in link check logic can
cause weird link stability issues if auto-negotiation fails.

Reported-by: Dean Nelson <[email protected]>
Signed-off-by: Tushar Dave <[email protected]>
Reviewed-by: Bruce Allan <[email protected]>
Tested-by: Jeff Pieper <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/net/e1000e/82571.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/e1000e/82571.c
+++ b/drivers/net/e1000e/82571.c
@@ -1573,6 +1573,9 @@ static s32 e1000_check_for_serdes_link_8
        ctrl = er32(CTRL);
        status = er32(STATUS);
        rxcw = er32(RXCW);
+       /* SYNCH bit and IV bit are sticky */
+       udelay(10);
+       rxcw = er32(RXCW);
 
        if ((rxcw & E1000_RXCW_SYNCH) && !(rxcw & E1000_RXCW_IV)) {
 


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