hi-actually yes, we should probably be using this instead of just dropping this. Also, I didn't write this code originally I just refactored a bunch of it - Dave Airlied is the original author, but the original version of this code was written ages ago. tbh, I think it's a safe bet to say that they probably did mean to use this but forgot to and no one noticed until now.
Hi,
Any clue about how to use crc value ? Does it have to be checked against something else ? If crc are not matching what should we do of the data copied just before ?
We should be able to just take the CRC value from the sideband message and then generate our own CRC value using the sideband message contents, and check if the two are equal. If they aren't, something went wrong and we didn't receive the message properly.
Now as to what we should do when we have CRC mismatches? That's a bit more difficult. If you have access to the DP MST spec, I suppose a place to start figuring that out would be checking if there's a way for us to request that a branch device resend whatever message it sent previously. If there isn't, I guess we should just print an error in dmesg (possibly with a hexdump of the failed message as well) and not forward the message to the driver. Not sure of any better way of handling it then that
Yeah I think this reflects what I wanted to do, I've no memory of a retransmit option in the spec, but I've away from it for a while. But we'd want to compare the CRC with what we got to make sure the are the same.
Dave.