[PATCH] wifi: mt76: mt7996: exclude tx backoff time from airtime

[Chad Monroe]

This helps to make STA airtime counters more accurate.

Signed-off-by: Chad Monroe <chad at monroe.io>
Suggested-by: Ryder Lee <ryder.lee at mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/mt7996/init.c | 4 ++++
 drivers/net/wireless/mediatek/mt76/mt7996/regs.h | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/init.c b/drivers/net/wireless/mediatek/mt76/mt7996/init.c
index f6a010b61a8a..afc4884f7ba2 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/init.c
@@ -460,6 +460,10 @@ mt7996_mac_init_band(struct mt7996_dev *dev, u8 band)
 	mt76_clear(dev, MT_WF_RMAC_MIB_AIRTIME4(band),
 		   MT_WF_RMAC_MIB_QOS23_BACKOFF);
 
+	/* clear backoff time for Tx duration */
+	mt76_clear(dev, MT_WTBLOFF_ACR(band),
+		   MT_WTBLOFF_ADM_BACKOFFTIME);
+
 	/* clear backoff time and set software compensation for OBSS time */
 	mask = MT_WF_RMAC_MIB_OBSS_BACKOFF | MT_WF_RMAC_MIB_ED_OFFSET;
 	set = FIELD_PREP(MT_WF_RMAC_MIB_OBSS_BACKOFF, 0) |
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/regs.h b/drivers/net/wireless/mediatek/mt76/mt7996/regs.h
index 06e307b5b02e..1876a968c92d 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/regs.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/regs.h
@@ -175,6 +175,9 @@ enum offs_rev {
 #define MT_WTBLOFF_RSCR_RCPI_MODE		GENMASK(31, 30)
 #define MT_WTBLOFF_RSCR_RCPI_PARAM		GENMASK(25, 24)
 
+#define MT_WTBLOFF_ACR(_band)			MT_WTBLOFF(_band, 0x010)
+#define MT_WTBLOFF_ADM_BACKOFFTIME		BIT(29)
+
 /* ETBF: band 0(0x820ea000), band 1(0x820fa000), band 2(0x830ea000) */
 #define MT_WF_ETBF_BASE(_band)			__BASE(WF_ETBF_BASE, (_band))
 #define MT_WF_ETBF(_band, ofs)			(MT_WF_ETBF_BASE(_band) + (ofs))
-- 
2.39.5