On Fri Jun 19 2020, Andrew Lunn wrote: >> > The switch is 100/100Mbps right? The MAC is only Fast ethernet. Do you >> > need some properties in the port@0 node to tell the switch to only use >> > 100Mbps? I would expect it to default to 1G. Not looked at the code >> > yet... >> >> No, that is not needed. That is a hardware configuration and AFAIK >> cannot be changed at run time. > > I was wondering about that in general. I did not spot any code in the > driver dealing with results from the PHY auto-neg. So you are saying > the CPU is fixed speed, by strapping? But what about the other ports? > Does the MAC need to know the PHY has negotiated 10Half, not 1G? Would > that not make a difference to your TSN?
Indeed, that does make a difference. I've checked with the vendor. The current version of the switch IP does not support configuring the speed etc. at run time. It is hard wired to 100 Mbit/s or 1000 Mbit/s for now. Later versions of the chip might support setting the speed etc. via configuration registers. As a result the PHYs at the front ports should be programmed to only advertise 100 Mbit/s or 1G depending on the hardware setup. Thanks, Kurt
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