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

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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: 05bd97fc55 ("net: dsa: Add Vitesse VSC73xx DSA router driver")
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pawel Dembicki 2024-08-09 21:38:04 +02:00 committed by David S. Miller
parent 5b9eebc2c7
commit fa63c6434b
1 changed files with 36 additions and 1 deletions
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37
drivers/net/dsa/vitesse-vsc73xx-core.c
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@ -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