lkml.org 
[lkml]   [2021]   [Nov]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.10 033/121] mdio: aspeed: Fix "Link is Down" issue
    Date
    From: Dylan Hung <dylan_hung@aspeedtech.com>

    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 <joel@jms.id.au>
    Signed-off-by: Dylan Hung <dylan_hung@aspeedtech.com>
    Reviewed-by: Andrew Lunn <andrew@lunn.ch>
    Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
    Link: https://lore.kernel.org/r/20211125024432.15809-1-dylan_hung@aspeedtech.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    drivers/net/mdio/mdio-aspeed.c | 7 +++++++
    1 file changed, 7 insertions(+)

    --- 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_b

    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,

    \
     
     \ /
      Last update: 2021-11-29 23:36    [W:3.172 / U:0.376 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site