3.16.72-rc1 review patch. If anyone has any objections, please let me know.
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From: Heiner Kallweit hkallweit1@gmail.com
commit d29f5aa0bc0c321e1b9e4658a2a7e08e885da52a upstream.
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@electromag.com.au Tested-by: liweihang liweihang@hisilicon.com Signed-off-by: Heiner Kallweit hkallweit1@gmail.com Reviewed-by: Florian Fainelli f.fainelli@gmail.com Signed-off-by: David S. Miller davem@davemloft.net [bwh: Backported to 3.16: open-code phy_set_bits()] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -1072,7 +1072,10 @@ int genphy_soft_reset(struct phy_device { int ret;
- ret = phy_write(phydev, MII_BMCR, BMCR_RESET); + ret = phy_read(phydev, MII_BMCR); + if (ret < 0) + return ret; + ret = phy_write(phydev, MII_BMCR, ret | BMCR_RESET); if (ret < 0) return ret;