| Message ID | 1428092835-16834-17-git-send-email-jeffrey.t.kirsher@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Jeff Kirsher |
| Headers | show |
On Fri, 2015-04-03 at 13:27 -0700, Jeff Kirsher wrote: > Add a header comment explaining why we have the somewhat crazy mailbox > flow. This flow is necessary as it prevents the PF<->SM mailbox from > being flooded by the VF messages, which normally trigger a message to > the PF. This helps prevent the case where we see a PF mailbox timeout. > > Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> > Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> > Acked-by: Matthew Vick <matthew.vick@intel.com> > --- > drivers/net/ethernet/intel/fm10k/fm10k_iov.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) I have applied to my queue.
-----Original Message----- From: Kirsher, Jeffrey T Sent: Friday, April 3, 2015 2:05 PM To: intel-wired-lan@lists.osuosl.org Cc: Keller, Jacob E; Singh, Krishneil K Subject: Re: [net-next 17/25] fm10k: comment next_vf_mbx flow On Fri, 2015-04-03 at 13:27 -0700, Jeff Kirsher wrote: > Add a header comment explaining why we have the somewhat crazy mailbox > flow. This flow is necessary as it prevents the PF<->SM mailbox from > being flooded by the VF messages, which normally trigger a message to > the PF. This helps prevent the case where we see a PF mailbox timeout. > > Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> > Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> > Acked-by: Matthew Vick <matthew.vick@intel.com> > --- > drivers/net/ethernet/intel/fm10k/fm10k_iov.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) I have applied to my queue. -- git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue.git dev-queue Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_iov.c b/drivers/net/ethernet/intel/fm10k/fm10k_iov.c index 1071f38..ce361cf 100644 --- a/drivers/net/ethernet/intel/fm10k/fm10k_iov.c +++ b/drivers/net/ethernet/intel/fm10k/fm10k_iov.c @@ -113,6 +113,13 @@ s32 fm10k_iov_mbx(struct fm10k_intfc *interface) /* lock the mailbox for transmit and receive */ fm10k_mbx_lock(interface); + /* Most VF messages sent to the PF cause the PF to respond by + * requesting from the SM mailbox. This means that too many VF + * messages processed at once could cause a mailbox timeout on the PF. + * To prevent this, store a pointer to the next VF mbx to process. Use + * that as the start of the loop so that we don't starve whichever VF + * got ignored on the previous run. + */ process_mbx: for (i = iov_data->next_vf_mbx ? : iov_data->num_vfs; i--;) { struct fm10k_vf_info *vf_info = &iov_data->vf_info[i]; @@ -141,6 +148,10 @@ process_mbx: mbx->ops.process(hw, mbx); } + /* if we stopped processing mailboxes early, update next_vf_mbx. + * Otherwise, reset next_vf_mbx, and restart loop so that we process + * the remaining mailboxes we skipped at the start. + */ if (i >= 0) { iov_data->next_vf_mbx = i + 1; } else if (iov_data->next_vf_mbx) {