ibmvnic: init ->running_cap_crqs early
We use ->running_cap_crqs to determine when the ibmvnic_tasklet() should send out the next protocol message type. i.e when we get back responses to all our QUERY_CAPABILITY CRQs we send out REQUEST_CAPABILITY crqs. Similiary, when we get responses to all the REQUEST_CAPABILITY crqs, we send out the QUERY_IP_OFFLOAD CRQ. We currently increment ->running_cap_crqs as we send out each CRQ and have the ibmvnic_tasklet() send out the next message type, when this running_cap_crqs count drops to 0. This assumes that all the CRQs of the current type were sent out before the count drops to 0. However it is possible that we send out say 6 CRQs, get preempted and receive all the 6 responses before we send out the remaining CRQs. This can result in ->running_cap_crqs count dropping to zero before all messages of the current type were sent and we end up sending the next protocol message too early. Instead initialize the ->running_cap_crqs upfront so the tasklet will only send the next protocol message after all responses are received. Use the cap_reqs local variable to also detect any discrepancy (either now or in future) in the number of capability requests we actually send. Currently only send_query_cap() is affected by this behavior (of sending next message early) since it is called from the worker thread (during reset) and from application thread (during ->ndo_open()) and they can be preempted. send_request_cap() is only called from the tasklet which processes CRQ responses sequentially, is not be affected. But to maintain the existing symmtery with send_query_capability() we update send_request_capability() also. Fixes: 249168ad ("ibmvnic: Make CRQ interrupt tasklet wait for all capabilities crqs") Signed-off-by:Sukadev Bhattiprolu <sukadev@linux.ibm.com> Reviewed-by:
Dany Madden <drt@linux.ibm.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
parent
db9f0e8b
Please register or sign in to comment