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| author | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2015-04-03 22:27:07 +0200 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2015-04-15 00:48:17 +0200 |
| commit | ada2411d4fce4c55cfe04cdd9ed3dc2c5fe6523a (patch) | |
| tree | 52d3c3998fd9f3d8722ef8d5fa9e7cb5b42bcf30 | |
| parent | fm10k: don't handle mailbox events in iov_event path and always process mailbox (diff) | |
| download | linux-ada2411d4fce4c55cfe04cdd9ed3dc2c5fe6523a.tar.xz linux-ada2411d4fce4c55cfe04cdd9ed3dc2c5fe6523a.zip | |
fm10k: comment next_vf_mbx flow
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>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
| -rw-r--r-- | drivers/net/ethernet/intel/fm10k/fm10k_iov.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_iov.c b/drivers/net/ethernet/intel/fm10k/fm10k_iov.c index 0b37e197e300..5b08e6284a3c 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]; @@ -137,6 +144,10 @@ 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) { |