Re: ibm_newemac tx problem with jumbo frame enabled

On Thu, Dec 8, 2011 at 3:33 AM, Benjamin Herrenschmidt <
benh@kernel.crashing.org> wrote:

On Wed, 2011-12-07 at 13:35 +0530, Prashant Bhole wrote:

quoted

Still couldn't find anything like fifo overflow...
I noticed one more thing, this problem happens only when mtu size on
the initiator (the other end) is set to 4088, regardless of any mtu
size set for EMAC.

Did you check all the registers that may carry errors ? Nothing showed
up ? Did you check that things like Pause frames were properly
negociated on both sides ? Tried playing with the pause and FIFO
thresholds ?

Other than using the tx timeout to perform resets I don't see a good way
to fix that problem.

Cheers,
Ben.

I checked RX descriptor status and TX descriptor status and ethtool output.
However I don't know about pause packet/frame, how do I check if pause
frames are properly negotiated on both sides?
I need to try changing pause and FIFO thresholds.

ethtool output after disconnection is as follows:
# ethtool -S eth0
NIC statistics:
     rx_packets: 330939
     rx_bytes: 804963241
     tx_packets: 248554
     tx_bytes: 798853638
     rx_packets_csum: 330716
     tx_packets_csum: 179526
     tx_undo: 0
     rx_dropped_stack: 0
     rx_dropped_oom: 0
     rx_dropped_error: 0
     rx_dropped_resize: 0
     rx_dropped_mtu: 0
     rx_stopped: 0
     rx_bd_errors: 0
     rx_bd_overrun: 0
     rx_bd_bad_packet: 0
     rx_bd_runt_packet: 0
     rx_bd_short_event: 0
     rx_bd_alignment_error: 0
     rx_bd_bad_fcs: 0
     rx_bd_packet_too_long: 0
     rx_bd_out_of_range: 0
     rx_bd_in_range: 0
     rx_parity: 0
     rx_fifo_overrun: 0
     rx_overrun: 0
     rx_bad_packet: 0
     rx_runt_packet: 0
     rx_short_event: 0
     rx_alignment_error: 0
     rx_bad_fcs: 0
     rx_packet_too_long: 0
     rx_out_of_range: 0
     rx_in_range: 0
     tx_dropped: 0
     tx_bd_errors: 0
     tx_bd_bad_fcs: 0
     tx_bd_carrier_loss: 0
     tx_bd_excessive_deferral: 0
     tx_bd_excessive_collisions: 0
     tx_bd_late_collision: 0
     tx_bd_multple_collisions: 0
     tx_bd_single_collision: 0
     tx_bd_underrun: 0
     tx_bd_sqe: 0
     tx_parity: 0
     tx_underrun: 0
     tx_sqe: 0
     tx_errors: 0


Thanks,
Prashant