Hi Kishon, On Wed, 2021-01-27 at 18:04 +0530, Kishon Vijay Abraham I wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the > content is safe >
... > > > > > > I'm not familiar with Ethernet. Are these generic media types? what > > > does > > > SR or DAC refer to? > > > > The SR stands for Short Reach and is a fiber type connection used by > > SFPs. There also other "reach" variants. > > > > DAC stands for Direct Attach Copper and is a type of cable that plugs > > into an SFP cage and provides information back to the user via its > > EEPROM regarding supported speed and capabilities in general. These > > typically supports speed of 5G or more. > > > > The SFP/Phylink is the "out-of-band" method that provides the type of > > connection: speed and media type that allows the client to adapt the > > SerDes configuration to the type of media selected by the user. > > > > > Are there other media types? What is the out-of-band > > > mechanism by which the controller gets the media type? Why was this > > > not > > > required for other existing Ethernet SERDES? > > > > This is probably a matter of the interface speed are now getting higher > > and the amount of configuration needed for the SerDes have increased, > > at the same time as this is not being a static setup, because the user > > an plug and unplug media to the SFP cage. > > > > > Are you aware of any other > > > vendors who might require this? > > > > I suspect that going forward it will become more widespread, at least > > we have more chips in the pipeline that need this SerDes for high speed > > connectivity. > > For this case I would recommend to add new API, something like > phy_set_media(). Configure() and Validate() is more for probing > something that is supported by SERDES and changing the parameters. But > in this case, I'd think the media type is determined by the cable that > is connected and cannot be changed. > > Thanks > Kishon I assume that you would like a separate interface for the speed information as well? Thanks for your comments. BR Steen
