Re: igb mtu change

On Thu, Oct 18, 2012 at 1:39 AM, Alexander Duyck
[off-list ref] wrote:

The current igb driver does receive the frame data into 2K buffers, and
transmits up to MTU size.  The only limitation on the size of the frame
you can transmit is the netdev->mtu which the driver doesn't evaluate.
It is evaluated at the network stack level.  The igb driver can send up
to 9K frames, in addition it can TSO up to 64K frames and send them in
9K chunks so I am not sure what you are asking.

Thanks,

Alex

Thanks a lot.
I am using igb-3.3.6  for hardware   - vendor=0x8086, device=0x10e6
only CONFIG_IGB_DISABLE_PACKET_SPLIT defined.


I will explain my question in detail.


int  i = 0 ;
rx_desc = IGB_RX_DESC(rx_ring, i);

if(!(igb_test_staterr(rx_desc, E1000_RXD_STAT_EOP) ) {
     printk ( "part of Jumbo frame ...Not the last junk ");
}


If mtu is 1500,  and jumbo frame size is 9200.   I get the printk  -
part of Jumbo frame ...Not the last junk .

But if i change mtu to 9216,  the condition ,
!(igb_test_staterr(rx_desc, E1000_RXD_STAT_EOP) , looks like
never satisfied .

Thanks,
Ratheesh