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authorDylan Hung <[email protected]>2021-11-25 10:44:32 +0800
committerJakub Kicinski <[email protected]>2021-11-25 07:44:42 -0800
commit9dbe33cf371bd70330858370bdbc35c7668f00c3 (patch)
treee47ef638c9b706e94f3badd262eca41cc131baf3
parenteaeace60778e524a2820d0c0ad60bf80289e292c (diff)
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: [email protected] Fixes: f160e99462c6 ("net: phy: Add mdio-aspeed") Reviewed-by: Joel Stanley <[email protected]> Signed-off-by: Dylan Hung <[email protected]> Reviewed-by: Andrew Lunn <[email protected]> Reviewed-by: Russell King (Oracle) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
-rw-r--r--drivers/net/mdio/mdio-aspeed.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/net/mdio/mdio-aspeed.c b/drivers/net/mdio/mdio-aspeed.c
index cad820568f75..966c3b4ad59d 100644
--- a/drivers/net/mdio/mdio-aspeed.c
+++ b/drivers/net/mdio/mdio-aspeed.c
@@ -61,6 +61,13 @@ static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum)
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,
data & ASPEED_MDIO_DATA_IDLE,
ASPEED_MDIO_INTERVAL_US,