> > How useful is collision? How did you test this? How did you cause > > collisions to see if the LED actually worked? > Indeed I am not able to generate collision on my setup so I did not test > this > collision part. > My use case is that the hardware strap configuration that selects the LED > output mode > can not be trusted so I have to force configuration with software. I added > this collision > part because I wanted to cover all the LED configuration modes offered by > the PHY. There are a few things i want to avoid here: 1) Vendor SDK mentality. The hardware can do this, lets add a knob to make use of it. We end up with 100 of configuration knobs which nobody ever uses. Do you actually have a board where the strapping is wrong? Are you going to submit a .dts file making use of this option? 2) LEDs are the wild west, because it is not part of 802.3. Every vendor does it differently, and has their own special blinking patterns. My preference is to keep it simple to what people actually use. You cannot actually generate a collision, the developer who wants to add support for collision. I have to ask, is collision actually useful? > > As far as i can see, this is just a normal 100Base-T PHY. Everybody > > uses that point-to-point nowadays. If it was an 100Base-T1, with a > > shared medium, good old CSMA/CD then collision might actually be > > useful. > > > > I also disagree with not having software fallback: > > > > ip -s link show eth0 > > 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000 > > link/ether 80:ee:73:83:60:27 brd ff:ff:ff:ff:ff:ff > > RX: bytes packets errors dropped missed mcast > > 4382213540983 2947876747 0 0 0 154890 > > TX: bytes packets errors dropped carrier collsns > > 18742773651 197507119 0 0 0 0 > > > > collsns = 0. The information is there in a standard format. However, > > when did you last see it not 0? > > Ok, I could add the software callback but I will not be able to test it ... My personal experience is, anything not tested is broken... Think about what Russell actually said. That should give you a clue how to cause collisions. If not, go study history books about CSMA/CD. Andrew
