On Tue, May 16, 2017 at 03:09:17PM +0200, Rafa Corvillo wrote:

quoted

quoted

quoted

Adding 8 bytes (sky2->netdev->mtu + ETH_HLEN + VLAN_HLEN + 8
(EDSA_HLEN)) does not fix the error, because the interface keep
having a maximum length of 1518 bytes (sky2->netdev->mtu + ETH_HLEN
+ VLAN_HLEN).

Did you check the value being written to here:

         /*
          * The receiver hangs if it receives frames larger than the
          * packet buffer. As a workaround, truncate oversize frames, but
          * the register is limited to 9 bits, so if you do frames > 2052
          * you better get the MTU right!
          */
         thresh = sky2_get_rx_threshold(sky2);
         if (thresh > 0x1ff)
                 sky2_write32(hw, SK_REG(sky2->port, RX_GMF_CTRL_T), RX_TRUNC_OFF);
         else {
                 sky2_write16(hw, SK_REG(sky2->port, RX_GMF_TR_THR), thresh);
                 sky2_write32(hw, SK_REG(sky2->port, RX_GMF_CTRL_T), RX_TRUNC_ON);
         }


What is thresh?

The value of thresh is 380.

So that is 1528.

Yes, this is the result of the roundup function.

You could hack it and try 0x1ff.

I have forced the value of thresh to 0x1ff and the rx error still appears.

Also, check that in sky2_rx_add(), le->length is set to 4K.

The value of le->length is set to 1520.

Rafa