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| author | Vinicius Costa Gomes <vinicius.gomes@intel.com> | 2018-03-30 17:06:52 -0700 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2018-04-24 08:53:19 -0700 |
| commit | 2707df9773cd2cb8b0f35b8592431b301da9d352 (patch) | |
| tree | b1ab3956304e789c0c02c51abc26f4bddc149b17 | |
| parent | 39035bfdc3f18987aba04165060bfbfa10ffc1cd (diff) | |
| download | linux-2707df9773cd2cb8b0f35b8592431b301da9d352.tar.gz linux-2707df9773cd2cb8b0f35b8592431b301da9d352.tar.xz | |
igb: Fix the transmission mode of queue 0 for Qav mode
When Qav mode is enabled, queue 0 should be kept on Stream Reservation
mode. From the i210 datasheet, section 8.12.19:
"Note: Queue0 QueueMode must be set to 1b when TransmitMode is set to
Qav." ("QueueMode 1b" represents the Stream Reservation mode)
The solution is to give queue 0 the all the credits it might need, so
it has priority over queue 1.
A situation where this can happen is when cbs is "installed" only on
queue 1, leaving queue 0 alone. For example:
$ tc qdisc replace dev enp2s0 handle 100: parent root mqprio num_tc 3 \
map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 queues 1@0 1@1 2@2 hw 0
$ tc qdisc replace dev enp2s0 parent 100:2 cbs locredit -1470 \
hicredit 30 sendslope -980000 idleslope 20000 offload 1
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
| -rw-r--r-- | drivers/net/ethernet/intel/igb/igb_main.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index c1c0bc30a16d..cce7ada89255 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -1700,7 +1700,22 @@ static void igb_configure_cbs(struct igb_adapter *adapter, int queue, WARN_ON(hw->mac.type != e1000_i210); WARN_ON(queue < 0 || queue > 1); - if (enable) { + if (enable || queue == 0) { + /* i210 does not allow the queue 0 to be in the Strict + * Priority mode while the Qav mode is enabled, so, + * instead of disabling strict priority mode, we give + * queue 0 the maximum of credits possible. + * + * See section 8.12.19 of the i210 datasheet, "Note: + * Queue0 QueueMode must be set to 1b when + * TransmitMode is set to Qav." + */ + if (queue == 0 && !enable) { + /* max "linkspeed" idleslope in kbps */ + idleslope = 1000000; + hicredit = ETH_FRAME_LEN; + } + set_tx_desc_fetch_prio(hw, queue, TX_QUEUE_PRIO_HIGH); set_queue_mode(hw, queue, QUEUE_MODE_STREAM_RESERVATION); |