• Dejin Zheng's avatar
    net: phy: smsc: fix printing too many logs · 6d61f483
    Dejin Zheng authored
    Commit 7ae7ad2f ("net: phy: smsc: use phy_read_poll_timeout()
    to simplify the code") will print a lot of logs as follows when Ethernet
    cable is not connected:
    
    [    4.473105] SMSC LAN8710/LAN8720 2188000.ethernet-1:00: lan87xx_read_status failed: -110
    
    When wait 640 ms for check ENERGYON bit, the timeout should not be
    regarded as an actual error and an error message also should not be
    printed. due to a hardware bug in LAN87XX device, it leads to unstable
    detection of plugging in Ethernet cable when LAN87xx is in Energy Detect
    Power-Down mode. the workaround for it involves, when the link is down,
    and at each read_status() call:
    
    - disable EDPD mode, forcing the PHY out of low-power mode
    - waiting 640ms to see if we have any energy detected from the media
    - re-enable entry to EDPD mode
    
    This is presumably enough to allow the PHY to notice that a cable is
    connected, and resume normal operations to negotiate with the partner.
    The problem is that when no media is detected, the 640ms wait times
    out and this commit was modified to prints an error message. it is an
    inappropriate conversion by used phy_read_poll_timeout() to introduce
    this bug. so fix this issue by use read_poll_timeout() to replace
    phy_read_poll_timeout().
    
    Fixes: 7ae7ad2f ("net: phy: smsc: use phy_read_poll_timeout() to simplify the code")
    Reported-by: default avatarKevin Groeneveld <kgroeneveld@gmail.com>
    Signed-off-by: default avatarDejin Zheng <zhengdejin5@gmail.com>
    Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    6d61f483
smsc.c 8.15 KB