Commit 9dbe33cf authored by Dylan Hung's avatar Dylan Hung Committed by Jakub Kicinski

mdio: aspeed: Fix "Link is Down" issue

The issue happened randomly in runtime.  The message "Link is Down" is
popped but soon it recovered to "Link is Up".

The "Link is Down" results from the incorrect read data for reading the
PHY register via MDIO bus.  The correct sequence for reading the data
shall be:
1. fire the command
2. wait for command done (this step was missing)
3. wait for data idle
4. read data from data register

Cc: stable@vger.kernel.org
Fixes: f160e994 ("net: phy: Add mdio-aspeed")
Reviewed-by: default avatarJoel Stanley <joel@jms.id.au>
Signed-off-by: default avatarDylan Hung <dylan_hung@aspeedtech.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Reviewed-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20211125024432.15809-1-dylan_hung@aspeedtech.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent eaeace60
...@@ -61,6 +61,13 @@ static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum) ...@@ -61,6 +61,13 @@ static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum)
iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL); iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL);
rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl,
!(ctrl & ASPEED_MDIO_CTRL_FIRE),
ASPEED_MDIO_INTERVAL_US,
ASPEED_MDIO_TIMEOUT_US);
if (rc < 0)
return rc;
rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data, rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data,
data & ASPEED_MDIO_DATA_IDLE, data & ASPEED_MDIO_DATA_IDLE,
ASPEED_MDIO_INTERVAL_US, ASPEED_MDIO_INTERVAL_US,
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment