On Fri, 11 Feb 2022 09:57:31 +0100 Morten Brørup <m...@smartsharesystems.com> wrote:
> > From: Bly, Mike [mailto:m...@ciena.com] > > Sent: Friday, 11 February 2022 02.30 > > > > Hello, > > > > This is in regards to the DPDK E1000 driver used for the i350 [8086:1521] > > NIC. > > > > I am looking to see if we can get forced speed == 1000Mb (1Gb) support > > working on this NIC. The current DPDK driver does not appear to have > > support for forcing the NIC to 1G (1000M) speed. It only supports setting > > 100M and 10M. Is there a reason for this? Refer to: > > e1000_phy_force_speed_duplex_setup() in drivers/net/e1000/base/e1000_phy.c. > > > > Based on my reading of ethernet-controller-i350-datasheet.pdf it would seem > > we should be able to force the speed to 1G. However, even after "updating" > > the above mentioned function to try and support a 1G forced speed, the only > > way we can get two of these NICs to link up to each other at 1G, is to set > > the port to auto-neg. We can certainly force speed on one link to 100M or > > 10M and the other NIC will link up, but no luck for 1G, regardless of > > whether we have one or both sides in a forced speed vs. auto-neg mode. > > > > Is there a limitation I missed in the PDF perhaps? > > Hi Mike, > > Auto-negotiation is a *requirement* for 1 Gbps according to the IEEE 802.3 > Ethernet standard, so the way to force 1 Gbps is: Enable auto-negotiation and > only advertise 1 Gbps. > > In other words: You cannot establish a 1 Gbps link without auto-neg. > > > Med venlig hilsen / Kind regards, > -Morten Brørup > Also, check your cable. 1G requires all 4 wire pairs to be connected. But 100M can get by with 2 pairs
