From 18c532e44939caa17f1fa380f7ac50dbc0718dbb Mon Sep 17 00:00:00 2001
From: Aminuddin Jamaluddin <aminuddin.jamaluddin@intel.com>
Date: Mon, 14 Nov 2022 14:53:02 +0800
Subject: [PATCH] net: phy: marvell: add sleep time after enabling the loopback bit
Git-commit: 18c532e44939caa17f1fa380f7ac50dbc0718dbb
Patch-mainline: v6.1-rc6
References: git-fixes

Sleep time is added to ensure the phy to be ready after loopback
bit was set. This to prevent the phy loopback test from failing.

Fixes: 020a45aff119 ("net: phy: marvell: add Marvell specific PHY loopback")
Cc: <stable@vger.kernel.org> # 5.15.x
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Signed-off-by: Aminuddin Jamaluddin <aminuddin.jamaluddin@intel.com>
Link: https://lore.kernel.org/r/20221114065302.10625-1-aminuddin.jamaluddin@intel.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/phy/marvell.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
index 2810f4f9da0c..0d706ee266af 100644
--- a/drivers/net/phy/marvell.c
+++ b/drivers/net/phy/marvell.c
@@ -2015,14 +2015,16 @@ static int m88e1510_loopback(struct phy_device *phydev, bool enable)
 		if (err < 0)
 			return err;
 
-		/* FIXME: Based on trial and error test, it seem 1G need to have
-		 * delay between soft reset and loopback enablement.
-		 */
-		if (phydev->speed == SPEED_1000)
-			msleep(1000);
+		err = phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK,
+				 BMCR_LOOPBACK);
 
-		return phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK,
-				  BMCR_LOOPBACK);
+		if (!err) {
+			/* It takes some time for PHY device to switch
+			 * into/out-of loopback mode.
+			 */
+			msleep(1000);
+		}
+		return err;
 	} else {
 		err = phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK, 0);
 		if (err < 0)
-- 
2.35.3