From: John Allen Date: Thu, 18 Jan 2018 22:27:12 +0000 (-0600) Subject: ibmvnic: Revert to previous mtu when unsupported value requested X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=e791380340685698dbdd38c7e3f3fcbf70a3c832;p=linux.git ibmvnic: Revert to previous mtu when unsupported value requested If we request an unsupported mtu value, the vnic server will suggest a different value. Currently we take the suggested value without question and login with that value. However, the behavior doesn't seem completely sane as attempting to change the mtu to some specific value will change the mtu to some completely different value most of the time. This patch fixes the issue by logging in with the previously used mtu value and printing an error message saying that the given mtu is unsupported. Signed-off-by: John Allen Reviewed-by: Nathan Fontenot Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 7f75d01432eff..cc36b254917cc 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -3623,7 +3623,17 @@ static void handle_request_cap_rsp(union ibmvnic_crq *crq, *req_value, (long int)be64_to_cpu(crq->request_capability_rsp. number), name); - *req_value = be64_to_cpu(crq->request_capability_rsp.number); + + if (be16_to_cpu(crq->request_capability_rsp.capability) == + REQ_MTU) { + pr_err("mtu of %llu is not supported. Reverting.\n", + *req_value); + *req_value = adapter->fallback.mtu; + } else { + *req_value = + be64_to_cpu(crq->request_capability_rsp.number); + } + ibmvnic_send_req_caps(adapter, 1); return; default: