Re: [Bonding-devel] Re: Bonding driver unreliable under high CPU load

[Jeff Garzik <jgarzik@xxxxxxxxxxxxxxxx>]

Cureington, Tony wrote:
>                 /* Yes, the mii is overlaid on the ifreq.ifr_ifru */
>                 mii = (struct mii_ioctl_data *)&ifr.ifr_data;
>                 if (ioctl(dev, &ifr, SIOCGMIIPHY) != 0) {
>                         return MII_LINK_READY;   /* can't tell */
>                 }
>
>                 mii->reg_num = 1;
>                 if (ioctl(dev, &ifr, SIOCGMIIREG) == 0) {
>                         /*
>                          * mii->val_out contains MII reg 1, BMSR
>                          * 0x0004 means link established
>                          */
>                         return mii->val_out;
>                 }


Speaking of bonding, I wonder about the above code -- why do you return 
mii->val_out directly?  AFAICS you should test BMSR_LSTATUS (a.k.a. 
0x0004) and return MII_LINK_READY or zero -- not a bunch of random bits.

The status word can certainly be non-zero even when link is absent.

Also, a further question:  do you have access to the slave struct 
net_device?  If so, just test netif_carrier_ok(slave_dev) and avoid all 
that ioctl calling if it returns non-zero.

        Jeff