• Jaeden Amero's avatar
    net/phy: micrel: Center FLP timing at 16ms · 6270e1ae
    Jaeden Amero authored
    Link failures have been observed when using the KSZ9031 with HP 1810-8G
    and HP 1910-8G network switches. Center the FLP timing at 16ms to help
    avoid intermittent link failures.
    
    >From the KSZ9031RNX and KSZ9031MNX data sheets revision 2.2, section
    "Auto-Negotiation Timing":
    	The KSZ9031[RNX or MNX] Fast Link Pulse (FLP) burst-to-burst
    	transmit timing for Auto-Negotiation defaults to 8ms. IEEE 802.3
    	Standard specifies this timing to be 16ms +/-8ms. Some PHY link
    	partners need to receive the FLP with 16ms centered timing;
    	otherwise, there can be intermittent link failures and long
    	link-up times.
    
    The PHY data sheet recommends configuring the FLP burst registers after
    power-up/reset and immediately thereafter restarting auto-negotiation, so
    we center the FLP timing at 16ms and then restart auto-negotiation in the
    config_init for KSZ9031.
    Signed-off-by: default avatarJaeden Amero <jaeden.amero@ni.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    6270e1ae
micrel.c 21.9 KB