Sun, Jan 31, 2021 at 06:09:24PM CET, dsahern@gmail.com wrote:

On 1/30/21 7:19 AM, Jiri Pirko wrote:

quoted

Fri, Jan 29, 2021 at 06:31:59PM CET, andrew@lunn.ch wrote:

quoted

quoted

Platform line card driver is aware of line card I2C topology, its
responsibility is to detect line card basic hardware type, create I2C
topology (mux), connect all the necessary I2C devices, like hotswap
devices, voltage and power regulators devices, iio/a2d devices and line
card EEPROMs, creates LED instances for LED located on a line card, exposes
line card related attributes, like CPLD and FPGA versions, reset causes,
required powered through line card hwmon interface.

So this driver, and the switch driver need to talk to each other, so
the switch driver actually knows what, if anything, is in the slot.

Not possible in case the BMC is a different host, which is common
scenario.

User provisions a 4 port card, but a 2 port card is inserted. How is
this detected and the user told the wrong card is inserted?

The card won't get activated.
The user won't see the type of inserted linecard. Again, it is not
possible for ASIC to access the linecard eeprom. See Vadim's reply.

If it is not detected that's a serious problem, no?

That is how it is, unfortunatelly.

If it is detected why can't the same mechanism be used for auto
provisioning?

Again, not possible to detect.