6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Pawel Dembicki paweldembicki@gmail.com
[ Upstream commit fa63c6434b6f6aaf9d8d599dc899bc0a074cc0ad ]
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: 05bd97fc559d ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/dsa/vitesse-vsc73xx-core.c | 37 +++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/net/dsa/vitesse-vsc73xx-core.c b/drivers/net/dsa/vitesse-vsc73xx-core.c index d8f368df8b06f..23bd8b3f89931 100644 --- a/drivers/net/dsa/vitesse-vsc73xx-core.c +++ b/drivers/net/dsa/vitesse-vsc73xx-core.c @@ -38,6 +38,10 @@ #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 */ @@ -196,6 +200,8 @@ #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 @@ -270,6 +276,7 @@ #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 { @@ -487,6 +494,22 @@ 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; @@ -494,12 +517,20 @@ 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; @@ -523,6 +554,10 @@ 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