On Wed, 13 Jan 2021 13:12:12 +0100 Jiri Pirko wrote: > This patchset introduces support for modular switch systems. > NVIDIA Mellanox SN4800 is an example of such. It contains 8 slots > to accomodate line cards. Available line cards include: > 16X 100GbE (QSFP28) > 8X 200GbE (QSFP56) > 4X 400GbE (QSFP-DD) > > Similar to split cabels, it is essencial for the correctness of > configuration and funcionality to treat the line card entities > in the same way, no matter the line card is inserted or not. > Meaning, the netdevice of a line card port cannot just disappear > when line card is removed. Also, system admin needs to be able > to apply configuration on netdevices belonging to line card port > even before the linecard gets inserted.
I don't understand why that would be. Please provide reasoning, e.g. what the FW/HW limitation is. > To resolve this, a concept of "provisioning" is introduced. > The user may "provision" certain slot with a line card type. > Driver then creates all instances (devlink ports, netdevices, etc) > related to this line card type. The carrier of netdevices stays down. > Once the line card is inserted and activated, the carrier of the > related netdevices goes up. Dunno what "line card" means for Mellovidia but I don't think the analogy of port splitting works. To my knowledge traditional line cards often carry processors w/ full MACs etc. so I'd say plugging in a line card is much more like plugging in a new NIC. There is no way to tell a breakout cable from normal one, so the system has no chance to magically configure itself. Besides SFP is just plugging a cable, not a module of the system..
