From: Dylan Hung Date: Thu, 25 Nov 2021 02:44:32 +0000 (+0800) Subject: mdio: aspeed: Fix "Link is Down" issue X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9ed3dc3968adb9fcaaa17d30fa4a037d071405d4;p=linux.git mdio: aspeed: Fix "Link is Down" issue commit 9dbe33cf371bd70330858370bdbc35c7668f00c3 upstream. 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: f160e99462c6 ("net: phy: Add mdio-aspeed") Reviewed-by: Joel Stanley Signed-off-by: Dylan Hung Reviewed-by: Andrew Lunn Reviewed-by: Russell King (Oracle) Link: https://lore.kernel.org/r/20211125024432.15809-1-dylan_hung@aspeedtech.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/net/mdio/mdio-aspeed.c b/drivers/net/mdio/mdio-aspeed.c index cad820568f751..966c3b4ad59d1 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,