ath9k: fix PA linearization calibration related crash

Before PAPRD training can run, the card needs to have sent a packet for
thermal calibration. Sending a dummy packet with the PAPRD training flag
set causes a crash under some circumstance.
Fix the code by replacing the dummy tx with a delay that waits for a
real packet tx to have occurred.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 7 insertions, 8 deletions

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 64a00d2f18f2..e4b9f35343e5 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1775,6 +1775,8 @@ int ath9k_hw_reset(struct ath_hw *ah, struct ath9k_channel *chan,
                 /* Operating channel changed, reset channel calibration data */
                 memset(caldata, 0, sizeof(*caldata));
                 ath9k_init_nfcal_hist_buffer(ah, chan);
+        } else if (caldata) {
+                caldata->paprd_packet_sent = false;
         }
         ah->noise = ath9k_hw_getchan_noise(ah, chan);
 
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index ce7332c64efb..6599a75f01fe 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -405,6 +405,7 @@ struct ath9k_hw_cal_data {
         int8_t iCoff;
         int8_t qCoff;
         bool rtt_done;
+        bool paprd_packet_sent;
         bool paprd_done;
         bool nfcal_pending;
         bool nfcal_interference;
diff --git a/drivers/net/wireless/ath/ath9k/link.c b/drivers/net/wireless/ath/ath9k/link.c
index 1c241921f95e..825a29cc9313 100644
--- a/drivers/net/wireless/ath/ath9k/link.c
+++ b/drivers/net/wireless/ath/ath9k/link.c
@@ -256,7 +256,7 @@ void ath_paprd_calibrate(struct work_struct *work)
         int len = 1800;
         int ret;
 
-        if (!caldata)
+        if (!caldata || !caldata->paprd_packet_sent || caldata->paprd_done)
                 return;
 
         ath9k_ps_wakeup(sc);
@@ -283,13 +283,6 @@ void ath_paprd_calibrate(struct work_struct *work)
                         continue;
 
                 chain_ok = 0;
-
-                ath_dbg(common, CALIBRATE,
-                        "Sending PAPRD frame for thermal measurement on chain %d\n",
-                        chain);
-                if (!ath_paprd_send_frame(sc, skb, chain))
-                        goto fail_paprd;
-
                 ar9003_paprd_setup_gain_table(ah, chain);
 
                 ath_dbg(common, CALIBRATE,
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 2c9da6b2ecb1..0d4155aec48d 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -2018,6 +2018,9 @@ static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,
 
         ath_dbg(common, XMIT, "TX complete: skb: %p\n", skb);
 
+        if (sc->sc_ah->caldata)
+                sc->sc_ah->caldata->paprd_packet_sent = true;
+
         if (!(tx_flags & ATH_TX_ERROR))
                 /* Frame was ACKed */
                 tx_info->flags |= IEEE80211_TX_STAT_ACK;