linux-kernel - [PATCH 4.19 276/639] net: phy: dont clear BMCR in genphy_soft

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200124093121.384723051@linuxfoundation.org>
Date:   Fri, 24 Jan 2020 10:27:26 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Phil Reid <preid@...ctromag.com.au>,
        liweihang <liweihang@...ilicon.com>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        "David S. Miller" <davem@...emloft.net>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 276/639] net: phy: dont clear BMCR in genphy_soft_reset

From: Heiner Kallweit <hkallweit1@...il.com>

[ Upstream commit d29f5aa0bc0c321e1b9e4658a2a7e08e885da52a ]

So far we effectively clear the BMCR register. Some PHY's can deal
with this (e.g. because they reset BMCR to a default as part of a
soft-reset) whilst on others this causes issues because e.g. the
autoneg bit is cleared. Marvell is an example, see also thread [0].
So let's be a little bit more gentle and leave all bits we're not
interested in as-is. This change is needed for PHY drivers to
properly deal with the original patch.

[0] https://marc.info/?t=155264050700001&r=1&w=2

Fixes: 6e2d85ec0559 ("net: phy: Stop with excessive soft reset")
Tested-by: Phil Reid <preid@...ctromag.com.au>
Tested-by: liweihang <liweihang@...ilicon.com>
Signed-off-by: Heiner Kallweit <hkallweit1@...il.com>
Reviewed-by: Florian Fainelli <f.fainelli@...il.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/phy/phy_device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 9c7e51443f6b6..ae40d8137fd20 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1657,7 +1657,7 @@ int genphy_soft_reset(struct phy_device *phydev)
 {
 	int ret;
 
-	ret = phy_write(phydev, MII_BMCR, BMCR_RESET);
+	ret = phy_set_bits(phydev, MII_BMCR, BMCR_RESET);
 	if (ret < 0)
 		return ret;
 
-- 
2.20.1