[PATCH 2/2] ath10k: apply chainmask settings to vdev on creation.

[greearb at candelatech.com]

From: Ben Greear <greearb at candelatech.com>

It appears it takes more than just setting the
hardware's chainmask to make things work well.  Without
this patch, a vdev would only use 1x1 rates when chainmask
was set to 0x3.

Setting the 'nss' (number of spatial streams) on the vdev
helps the firmware's rate-control algorithm work properly.

Tested on CT firmware, but probably this works (and
is required) on normal firmware.

Signed-off-by: Ben Greear <greearb at candelatech.com>
---
 drivers/net/wireless/ath/ath10k/mac.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 4dc5a40..855c71c 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -2767,6 +2767,17 @@ static int ath10k_config(struct ieee80211_hw *hw, u32 changed)
 	return ret;
 }
 
+static u32 get_nss_from_chainmask(u16 chain_mask)
+{
+	if ((chain_mask & 0x15) == 0x15)
+		return 4;
+	else if ((chain_mask & 0x7) == 0x7)
+		return 3;
+	else if ((chain_mask & 0x3) == 0x3)
+		return 2;
+	return 1;
+}
+
 /*
  * TODO:
  * Figure out how to handle WMI_VDEV_SUBTYPE_P2P_DEVICE,
@@ -2868,6 +2879,19 @@ static int ath10k_add_interface(struct ieee80211_hw *hw,
 		goto err_vdev_delete;
 	}
 
+	if (ar->cfg_tx_chainmask) {
+		u16 nss = get_nss_from_chainmask(ar->cfg_tx_chainmask);
+		vdev_param = ar->wmi.vdev_param->nss;
+		ret = ath10k_wmi_vdev_set_param(ar, arvif->vdev_id, vdev_param,
+						nss);
+		if (ret) {
+			ath10k_warn(ar, "failed to set vdev %i chainmask 0x%x, nss %i: %d\n",
+				    arvif->vdev_id, ar->cfg_tx_chainmask, nss,
+				    ret);
+			goto err_vdev_delete;
+		}
+	}
+
 	if (arvif->vdev_type == WMI_VDEV_TYPE_AP) {
 		ret = ath10k_peer_create(ar, arvif->vdev_id, vif->addr);
 		if (ret) {
-- 
1.7.11.7