[PATCH 1/1] UBUNTU: SAUCE: e1000e: Increase polling timeout on MDIC ready bit

[Kai-Heng Feng]

BugLink: https://bugs.launchpad.net/bugs/1897755

We are seeing the following error after S3 resume:
[  704.746874] e1000e 0000:00:1f.6 eno1: Setting page 0x6020
[  704.844232] e1000e 0000:00:1f.6 eno1: MDI Write did not complete
[  704.902817] e1000e 0000:00:1f.6 eno1: Setting page 0x6020
[  704.903075] e1000e 0000:00:1f.6 eno1: reading PHY page 769 (or 0x6020 shifted) reg 0x17
[  704.903281] e1000e 0000:00:1f.6 eno1: Setting page 0x6020
[  704.903486] e1000e 0000:00:1f.6 eno1: writing PHY page 769 (or 0x6020 shifted) reg 0x17
[  704.943155] e1000e 0000:00:1f.6 eno1: MDI Error
...
[  705.108161] e1000e 0000:00:1f.6 eno1: Hardware Error

This patch only papers over the symptom, as we don't really know the
root cause of the issue. The most possible culprit is Intel ME, which
may do its own things that conflict with software.

Intel ethernet devs are aware of this issue, though they think this is
not the right solution. However, instead of papering over the cracks,
they don't have any solution either because they don't support ME under
Linux :)

Full discussion can be found here:
https://lore.kernel.org/lkml/20200923074751.10527-1-kai.heng.feng@canonical.com/

Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
 drivers/net/ethernet/intel/e1000e/phy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/e1000e/phy.c b/drivers/net/ethernet/intel/e1000e/phy.c
index e11c877595fb..e6d4acd90937 100644
--- a/drivers/net/ethernet/intel/e1000e/phy.c
+++ b/drivers/net/ethernet/intel/e1000e/phy.c
@@ -203,7 +203,7 @@ s32 e1000e_write_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 data)
 	 * Increasing the time out as testing showed failures with
 	 * the lower time out
 	 */
-	for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 3); i++) {
+	for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 10); i++) {
 		udelay(50);
 		mdic = er32(MDIC);
 		if (mdic & E1000_MDIC_READY)
-- 
2.17.1