Commit a243c2ef authored by Robert Foss's avatar Robert Foss Committed by David S. Miller
Browse files

net: asix: see 802.3 spec for phy reset 

From: Grant Grundler <grundler@chromium.org>

https://lkml.org/lkml/2014/11/11/947



Ben Hutchings is correct. IEEE 802.3 spec section "22.2.4.1.1 Reset" requires
up to 500ms delay. Mitigate the "max" delay by polling the phy until BCM_RESET
bit is clear.

Signed-off-by: default avatarGrant Grundler <grundler@chromium.org>
Signed-off-by: default avatarRobert Foss <robert.foss@collabora.com>
Tested-by: default avatarRobert Foss <robert.foss@collabora.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4c1442aa

drivers/net/usb/asix_devices.c

+24 −3
Original line number Diff line number Diff line
@@ -212,6 +212,28 @@ static const struct net_device_ops ax88172_netdev_ops = { 
	.ndo_set_rx_mode	= ax88172_set_multicast,

};



static void asix_phy_reset(struct usbnet *dev, unsigned int reset_bits)

{

	unsigned int timeout = 5000;



	asix_mdio_write(dev->net, dev->mii.phy_id, MII_BMCR, reset_bits);



	/* give phy_id a chance to process reset */

	udelay(500);



	/* See IEEE 802.3 "22.2.4.1.1 Reset": 500ms max */

	while (timeout--) {

		if (asix_mdio_read(dev->net, dev->mii.phy_id, MII_BMCR)

							& BMCR_RESET)

			udelay(100);

		else

			return;

	}



	netdev_err(dev->net, "BMCR_RESET timeout on phy_id %d\n",

		   dev->mii.phy_id);

}



static int ax88172_bind(struct usbnet *dev, struct usb_interface *intf)

{

	int ret = 0;
@@ -258,7 +280,7 @@ static int ax88172_bind(struct usbnet *dev, struct usb_interface *intf) 
	dev->net->needed_headroom = 4; /* cf asix_tx_fixup() */

	dev->net->needed_tailroom = 4; /* cf asix_tx_fixup() */



	asix_mdio_write(dev->net, dev->mii.phy_id, MII_BMCR, BMCR_RESET);

	asix_phy_reset(dev, BMCR_RESET);

	asix_mdio_write(dev->net, dev->mii.phy_id, MII_ADVERTISE,

		ADVERTISE_ALL | ADVERTISE_CSMA | ADVERTISE_PAUSE_CAP);

	mii_nway_restart(&dev->mii);
@@ -900,8 +922,7 @@ static int ax88178_reset(struct usbnet *dev) 
	} else if (data->phymode == PHY_MODE_RTL8211CL)

		rtl8211cl_phy_init(dev);



	asix_mdio_write(dev->net, dev->mii.phy_id, MII_BMCR,

			BMCR_RESET | BMCR_ANENABLE);

	asix_phy_reset(dev, BMCR_RESET | BMCR_ANENABLE);

	asix_mdio_write(dev->net, dev->mii.phy_id, MII_ADVERTISE,

			ADVERTISE_ALL | ADVERTISE_CSMA | ADVERTISE_PAUSE_CAP);

	asix_mdio_write(dev->net, dev->mii.phy_id, MII_CTRL1000,

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