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.
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
---
This patch came from net-next series[0].
Changes since net-next:
- removed mutex
- used method poll.h to poll busy value in 'vsc73xx_mdio_busy_check'
- use 'vsc73xx_mdio_busy_check' for control if mdio is ready
[0] https://patchwork.kernel.org/project/netdevbpf/patch/20240729210615.279952-6-paweldembicki@gmail.com/
---
drivers/net/dsa/vitesse-vsc73xx-core.c | 33 ++++++++++++++++++++++++--
1 file changed, 31 insertions(+), 2 deletions(-)
diff --git a/drivers/net/dsa/vitesse-vsc73xx-core.c b/drivers/net/dsa/vitesse-vsc73xx-core.c
index b6c46a3da9a5..42b4f312c418 100644
--- a/drivers/net/dsa/vitesse-vsc73xx-core.c
+++ b/drivers/net/dsa/vitesse-vsc73xx-core.c
@@ -317,6 +317,7 @@
#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 {
@@ -545,6 +546,22 @@ 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;
@@ -552,6 +569,10 @@ 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 = VSC73XX_MII_CMD_OPERATION |
FIELD_PREP(VSC73XX_MII_CMD_PHY_ADDR, phy) |
@@ -560,7 +581,11 @@ static int vsc73xx_phy_read(struct dsa_switch *ds, int phy, int regnum)
VSC73XX_MII_CMD, cmd);
if (ret)
return ret;
- msleep(2);
+
+ ret = vsc73xx_mdio_busy_check(vsc);
+ if (ret)
+ return ret;
+
ret = vsc73xx_read(vsc, VSC73XX_BLOCK_MII, VSC73XX_BLOCK_MII_INTERNAL,
VSC73XX_MII_DATA, &val);
if (ret)
@@ -583,7 +608,11 @@ static int vsc73xx_phy_write(struct dsa_switch *ds, int phy, int regnum,
{
struct vsc73xx *vsc = ds->priv;
u32 cmd;
- int ret;
+ int ret = 0;
+
+ 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
--
2.34.1