From d579c43c82f093e63639151625b2139166c730fd Mon Sep 17 00:00:00 2001
From: Malcolm Priestley <tvboxspy@gmail.com>
Date: Wed, 8 Jan 2020 21:41:20 +0000
Subject: [PATCH] staging: vt6656: use NULLFUCTION stack on mac80211
Git-commit: d579c43c82f093e63639151625b2139166c730fd
Patch-mainline: v5.6-rc1
References: bsc#1051510

It appears that the drivers does not go into power save correctly the
NULL data packets are not being transmitted because it not enabled
in mac80211.

The driver needs to capture ieee80211_is_nullfunc headers and
copy the duration_id to it's own duration data header.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Link: https://lore.kernel.org/r/610971ae-555b-a6c3-61b3-444a0c1e35b4@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/staging/vt6656/main_usb.c |    1 +
 drivers/staging/vt6656/rxtx.c     |   14 +++++---------
 2 files changed, 6 insertions(+), 9 deletions(-)

--- a/drivers/staging/vt6656/main_usb.c
+++ b/drivers/staging/vt6656/main_usb.c
@@ -983,6 +983,7 @@ vt6656_probe(struct usb_interface *intf,
 	ieee80211_hw_set(priv->hw, RX_INCLUDES_FCS);
 	ieee80211_hw_set(priv->hw, REPORTS_TX_ACK_STATUS);
 	ieee80211_hw_set(priv->hw, SUPPORTS_PS);
+	ieee80211_hw_set(priv->hw, PS_NULLFUNC_STACK);
 
 	priv->hw->max_signal = 100;
 
--- a/drivers/staging/vt6656/rxtx.c
+++ b/drivers/staging/vt6656/rxtx.c
@@ -277,11 +277,9 @@ static u16 vnt_rxtx_datahead_g(struct vn
 							PK_TYPE_11B, &buf->b);
 
 	/* Get Duration and TimeStamp */
-	if (ieee80211_is_pspoll(hdr->frame_control)) {
-		__le16 dur = cpu_to_le16(priv->current_aid | BIT(14) | BIT(15));
-
-		buf->duration_a = dur;
-		buf->duration_b = dur;
+	if (ieee80211_is_nullfunc(hdr->frame_control)) {
+		buf->duration_a = hdr->duration_id;
+		buf->duration_b = hdr->duration_id;
 	} else {
 		buf->duration_a = vnt_get_duration_le(priv,
 						tx_context->pkt_type, need_ack);
@@ -370,10 +368,8 @@ static u16 vnt_rxtx_datahead_ab(struct v
 			  tx_context->pkt_type, &buf->ab);
 
 	/* Get Duration and TimeStampOff */
-	if (ieee80211_is_pspoll(hdr->frame_control)) {
-		__le16 dur = cpu_to_le16(priv->current_aid | BIT(14) | BIT(15));
-
-		buf->duration = dur;
+	if (ieee80211_is_nullfunc(hdr->frame_control)) {
+		buf->duration = hdr->duration_id;
 	} else {
 		buf->duration = vnt_get_duration_le(priv, tx_context->pkt_type,
 						    need_ack);