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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Baruch Siach <baruch@tkos.co.il>,
        Andrew Lunn <andrew@lunn.ch>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.19 09/50] net: dsa: mv88e6xxx: wait after reset deactivation
Date:   Fri, 26 Jul 2019 17:24:44 +0200
Message-Id: <20190726152301.584679551@linuxfoundation.org>
In-Reply-To: <20190726152300.760439618@linuxfoundation.org>
References: <20190726152300.760439618@linuxfoundation.org>
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From: Baruch Siach <baruch@tkos.co.il>

[ Upstream commit 7b75e49de424ceb53d13e60f35d0a73765626fda ]

Add a 1ms delay after reset deactivation. Otherwise the chip returns
bogus ID value. This is observed with 88E6390 (Peridot) chip.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/dsa/mv88e6xxx/chip.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -4816,6 +4816,8 @@ static int mv88e6xxx_probe(struct mdio_d
 		err = PTR_ERR(chip->reset);
 		goto out;
 	}
+	if (chip->reset)
+		usleep_range(1000, 2000);
 
 	err = mv88e6xxx_detect(chip);
 	if (err)