[PATCH net v2] net: phy: broadcom: Add power down exit reset state delay

From: Florian Fainelli <f.fainelli@gmail.com>
To: netdev@vger.kernel.org
Cc: Florian Fainelli <f.fainelli@gmail.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Russell King <linux@armlinux.org.uk>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	bcm-kernel-feedback-list@broadcom.com (open list:BROADCOM
	ETHERNET PHY DRIVERS), linux-kernel@vger.kernel.org (open list)
Subject: [PATCH net v2] net: phy: broadcom: Add power down exit reset state delay
Date: Wed, 10 Mar 2021 20:53:42 -0800	[thread overview]
Message-ID: <20210311045343.3259383-1-f.fainelli@gmail.com> (raw)

Per the datasheet, when we clear the power down bit, the PHY remains in
an internal reset state for 40us and then resume normal operation.
Account for that delay to avoid any issues in the future if
genphy_resume() changes.

Fixes: fe26821fa614 ("net: phy: broadcom: Wire suspend/resume for BCM54810")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
Changes in v2:

- make it build by using flseep()

 drivers/net/phy/broadcom.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/phy/broadcom.c b/drivers/net/phy/broadcom.c
index fa0be591ae79..ad51f1889435 100644
--- a/drivers/net/phy/broadcom.c
+++ b/drivers/net/phy/broadcom.c
@@ -399,6 +399,11 @@ static int bcm54xx_resume(struct phy_device *phydev)
 	if (ret < 0)
 		return ret;
 
+	/* Upon exiting power down, the PHY remains in an internal reset state
+	 * for 40us
+	 */
+	fsleep(40);
+
 	return bcm54xx_config_init(phydev);
 }
 
-- 
2.25.1

