[PATCH v5 2/4] e1000e: bump up timeout to wait when ME un-configures ULP mode

[Mario Limonciello]

Per guidance from Intel ethernet architecture team, it may take
up to 1 second for unconfiguring ULP mode.

However in practice this seems to be taking up to 2 seconds on
some Lenovo machines.  Detect scenarios that take more than 1 second
but less than 2.5 seconds and emit a warning on resume for those
scenarios.

Suggested-by: Aaron Ma <aaron.ma@xxxxxxxxxxxxx>
Suggested-by: Sasha Netfin <sasha.neftin@xxxxxxxxx>
Suggested-by: Hans de Goede <hdegoede@xxxxxxxxxx>
CC: Mark Pearson <markpearson@xxxxxxxxxx>
Fixes: f15bb6dde738cc8fa0 ("e1000e: Add support for S0ix")
BugLink: https://bugs.launchpad.net/bugs/1865570
Link: https://patchwork.ozlabs.org/project/intel-wired-lan/patch/20200323191639.48826-1-aaron.ma@xxxxxxxxxxxxx/
Link: https://lkml.org/lkml/2020/12/13/15
Link: https://lkml.org/lkml/2020/12/14/708
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxxx>
---
 drivers/net/ethernet/intel/e1000e/ich8lan.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index 9aa6fad8ed47..fdf23d20c954 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -1240,6 +1240,9 @@ static s32 e1000_disable_ulp_lpt_lp(struct e1000_hw *hw, bool force)
 		return 0;
 
 	if (er32(FWSM) & E1000_ICH_FWSM_FW_VALID) {
+		struct e1000_adapter *adapter = hw->adapter;
+		bool firmware_bug = false;
+
 		if (force) {
 			/* Request ME un-configure ULP mode in the PHY */
 			mac_reg = er32(H2ME);
@@ -1248,16 +1251,23 @@ static s32 e1000_disable_ulp_lpt_lp(struct e1000_hw *hw, bool force)
 			ew32(H2ME, mac_reg);
 		}
 
-		/* Poll up to 300msec for ME to clear ULP_CFG_DONE. */
+		/* Poll up to 2.5 seconds for ME to clear ULP_CFG_DONE.
+		 * If this takes more than 1 second, show a warning indicating a firmware
+		 * bug */
 		while (er32(FWSM) & E1000_FWSM_ULP_CFG_DONE) {
-			if (i++ == 30) {
+			if (i++ == 250) {
 				ret_val = -E1000_ERR_PHY;
 				goto out;
 			}
+			if (i > 100 && !firmware_bug)
+				firmware_bug = true;
 
 			usleep_range(10000, 11000);
 		}
-		e_dbg("ULP_CONFIG_DONE cleared after %dmsec\n", i * 10);
+		if (firmware_bug)
+			e_warn("ULP_CONFIG_DONE took %dmsec.  This is a firmware bug\n", i * 10);
+		else
+			e_dbg("ULP_CONFIG_DONE cleared after %dmsec\n", i * 10);
 
 		if (force) {
 			mac_reg = er32(H2ME);
-- 
2.25.1