Re: [PATCH] net:phy: Fix "Link is Down" issue
From: Joel Stanley <joel@jms.id.au>
Date: 2021-11-24 10:06:01
Also in:
linux-arm-kernel, linux-aspeed, lkml
On Wed, 24 Nov 2021 at 06:11, Dylan Hung [off-list ref] wrote:
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
I consulted the datasheet and it doesn't mention this. Perhaps something to be added? Reviewed-by: Joel Stanley <joel@jms.id.au>
Fixes: a9770eac511a ("net: mdio: Move MDIO drivers into a new subdirectory")
I think this should be:
Fixes: f160e99462c6 ("net: phy: Add mdio-aspeed")
We should cc stable too.
quoted hunk ↗ jump to hunk
Signed-off-by: Dylan Hung <redacted> --- drivers/net/mdio/mdio-aspeed.c | 7 +++++++ 1 file changed, 7 insertions(+)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, --2.25.1