Commit fa63c643 authored by Pawel Dembicki's avatar Pawel Dembicki Committed by David S. Miller
Browse files

net: dsa: vsc73xx: check busy flag in MDIO operations 



The VSC73xx has a busy flag used during MDIO operations. It is raised
when MDIO read/write operations are in progress. Without it, PHYs are
misconfigured and bus operations do not work as expected.

Fixes: 05bd97fc ("net: dsa: Add Vitesse VSC73xx DSA router driver")
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarFlorian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: default avatarPawel Dembicki <paweldembicki@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5b9eebc2

drivers/net/dsa/vitesse-vsc73xx-core.c

+36 −1
Original line number Diff line number Diff line
@@ -40,6 +40,10 @@ 
#define VSC73XX_BLOCK_ARBITER	0x5 /* Only subblock 0 */

#define VSC73XX_BLOCK_SYSTEM	0x7 /* Only subblock 0 */



/* MII Block subblock */

#define VSC73XX_BLOCK_MII_INTERNAL	0x0 /* Internal MDIO subblock */

#define VSC73XX_BLOCK_MII_EXTERNAL	0x1 /* External MDIO subblock */



#define CPU_PORT	6 /* CPU port */



/* MAC Block registers */
@@ -225,6 +229,8 @@ 
#define VSC73XX_MII_CMD		0x1

#define VSC73XX_MII_DATA	0x2



#define VSC73XX_MII_STAT_BUSY	BIT(3)



/* Arbiter block 5 registers */

#define VSC73XX_ARBEMPTY		0x0c

#define VSC73XX_ARBDISC			0x0e
@@ -299,6 +305,7 @@ 
#define IS_739X(a) (IS_7395(a) || IS_7398(a))



#define VSC73XX_POLL_SLEEP_US		1000

#define VSC73XX_MDIO_POLL_SLEEP_US	5

#define VSC73XX_POLL_TIMEOUT_US		10000



struct vsc73xx_counter {
@@ -527,6 +534,22 @@ static int vsc73xx_detect(struct vsc73xx *vsc) 
	return 0;

}



static int vsc73xx_mdio_busy_check(struct vsc73xx *vsc)

{

	int ret, err;

	u32 val;



	ret = read_poll_timeout(vsc73xx_read, err,

				err < 0 || !(val & VSC73XX_MII_STAT_BUSY),

				VSC73XX_MDIO_POLL_SLEEP_US,

				VSC73XX_POLL_TIMEOUT_US, false, vsc,

				VSC73XX_BLOCK_MII, VSC73XX_BLOCK_MII_INTERNAL,

				VSC73XX_MII_STAT, &val);

	if (ret)

		return ret;

	return err;

}



static int vsc73xx_phy_read(struct dsa_switch *ds, int phy, int regnum)

{

	struct vsc73xx *vsc = ds->priv;
@@ -534,12 +557,20 @@ static int vsc73xx_phy_read(struct dsa_switch *ds, int phy, int regnum) 
	u32 val;

	int ret;



	ret = vsc73xx_mdio_busy_check(vsc);

	if (ret)

		return ret;



	/* Setting bit 26 means "read" */

	cmd = BIT(26) | (phy << 21) | (regnum << 16);

	ret = vsc73xx_write(vsc, VSC73XX_BLOCK_MII, 0, 1, cmd);

	if (ret)

		return ret;

	msleep(2);



	ret = vsc73xx_mdio_busy_check(vsc);

	if (ret)

		return ret;



	ret = vsc73xx_read(vsc, VSC73XX_BLOCK_MII, 0, 2, &val);

	if (ret)

		return ret;
@@ -563,6 +594,10 @@ static int vsc73xx_phy_write(struct dsa_switch *ds, int phy, int regnum, 
	u32 cmd;

	int ret;



	ret = vsc73xx_mdio_busy_check(vsc);

	if (ret)

		return ret;



	/* It was found through tedious experiments that this router

	 * chip really hates to have it's PHYs reset. They

	 * never recover if that happens: autonegotiation stops