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authorVinicius Costa Gomes <vinicius.gomes@intel.com>2018-03-30 17:06:52 -0700
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2018-04-24 08:53:19 -0700
commit2707df9773cd2cb8b0f35b8592431b301da9d352 (patch)
treeb1ab3956304e789c0c02c51abc26f4bddc149b17 /drivers/net/ethernet/intel/igb/igb_main.c
parentixgbevf: ensure xdp_ring resources are free'd on error exit (diff)
downloadlinux-dev-2707df9773cd2cb8b0f35b8592431b301da9d352.tar.xz
linux-dev-2707df9773cd2cb8b0f35b8592431b301da9d352.zip
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>
Diffstat (limited to 'drivers/net/ethernet/intel/igb/igb_main.c')
-rw-r--r--drivers/net/ethernet/intel/igb/igb_main.c17
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);