1:  236f85ca5b53 ! 1:  22344f2fa3f1 wifi: b43: keep the N-PHY TX power control from drifting while idle
    @@ Commit message
         load bit is set as frames go out, so keep it set until OFDM frames have
         been sent for a while. Until then, the base indices stay where they
         were loaded instead of drifting. Forget the indices when the power
    -    control is set up again or the channel changes.
    +    control is set up again or the channel changes. Only sample them once
    +    OFDM frames have been sent without a break for 200 ms, so the loop has
    +    settled first, and suspend the MAC around the register accesses.
     
         With this, the base indices stay at 75-79 over idle periods, and all
         pings after them get through. Throughput is unchanged.
    @@ drivers/net/wireless/broadcom/b43/main.c: static void b43_tx_work(struct work_st
      			else
     
      ## drivers/net/wireless/broadcom/b43/phy_n.c ##
    -@@ drivers/net/wireless/broadcom/b43/phy_n.c: static void b43_nphy_tx_power_ctrl(struct b43_wldev *dev, bool enable)
    - 		b43_nphy_stay_in_carrier_search(dev, 1);
    +@@ drivers/net/wireless/broadcom/b43/phy_n.c: static void b43_nphy_iq_cal_gain_params(struct b43_wldev *dev, u16 core,
    +  * Tx and Rx
    +  **************************************************/
      
    - 	nphy->txpwrctrl = enable;
    ++/*
    ++ * Forget the remembered TX power control base indices. Also move the last
    ++ * OFDM transmission into the past, so the next one is not taken as part of
    ++ * ongoing traffic: jiffies starts at -300 s on 32-bit, so a zero timestamp
    ++ * would look recent for the first five minutes after boot.
    ++ */
    ++static void b43_nphy_txpctl_bidx_reset(struct b43_wldev *dev)
    ++{
    ++	struct b43_phy_n *nphy = dev->phy.n;
    ++
     +	nphy->txpctl_bidx_valid = false;
    ++	nphy->txpctl_last_tx = jiffies - HZ;
     +	if (nphy->txpctl_bidx_loaded) {
     +		b43_phy_write(dev, B43_NPHY_TXPCTL_BIDX, 0);
     +		nphy->txpctl_bidx_loaded = false;
     +	}
    ++}
    ++
    + /* https://bcm-v4.sipsolutions.net/802.11/PHY/N/TxPwrCtrlEnable */
    + static void b43_nphy_tx_power_ctrl(struct b43_wldev *dev, bool enable)
    + {
    +@@ drivers/net/wireless/broadcom/b43/phy_n.c: static void b43_nphy_tx_power_ctrl(struct b43_wldev *dev, bool enable)
    + 		b43_nphy_stay_in_carrier_search(dev, 1);
    + 
    + 	nphy->txpwrctrl = enable;
    ++	b43_nphy_txpctl_bidx_reset(dev);
      	if (!enable) {
      		if (dev->phy.rev >= 3 &&
      		    (b43_phy_read(dev, B43_NPHY_TXPCTL_CMD) &
    @@ drivers/net/wireless/broadcom/b43/phy_n.c: static void b43_nphy_channel_setup(st
     + * them back when sending starts again after a pause. The base indices
     + * only take the loaded values while the load bit is set as frames go
     + * out, so it stays set until frames have been sent for a while. Until
    -+ * then, the base indices stay where they were loaded.
    ++ * then, the base indices stay where they were loaded. Only sample them
    ++ * once OFDM frames have been sent without a break for a while, so the
    ++ * loop has settled on them first.
    ++ *
    ++ * The MAC is suspended only around the register accesses, which happen
    ++ * at most every 20 ms while frames are sent.
     + */
     +void b43_nphy_txpctl_ofdm_tx(struct b43_wldev *dev)
     +{
     +	struct b43_phy_n *nphy = dev->phy.n;
     +	unsigned long now = jiffies;
    ++	bool load = false, unload = false, sample = false;
     +	u16 c1, c2;
     +
     +	if (dev->phy.rev < 3 || !nphy->txpwrctrl)
     +		return;
     +
     +	if (nphy->txpctl_bidx_valid &&
    -+	    time_after(now, nphy->txpctl_last_tx + HZ / 2)) {
    ++	    time_after(now, nphy->txpctl_last_tx + HZ / 2))
    ++		load = true;
    ++	else if (nphy->txpctl_bidx_loaded)
    ++		unload = time_after(now, nphy->txpctl_last_sample + HZ / 50);
    ++	else if (time_after_eq(now, nphy->txpctl_last_tx + HZ / 20))
    ++		/* Traffic starts again, give the loop time to settle */
    ++		nphy->txpctl_last_sample = now;
    ++	else
    ++		sample = time_after(now, nphy->txpctl_last_sample + HZ / 5);
    ++
    ++	nphy->txpctl_last_tx = now;
    ++	if (!load && !unload && !sample)
    ++		return;
    ++
    ++	b43_mac_suspend(dev);
    ++	if (nphy->hang_avoid)
    ++		b43_nphy_stay_in_carrier_search(dev, 1);
    ++
    ++	if (load) {
     +		b43_phy_write(dev, B43_NPHY_TXPCTL_BIDX,
     +			      B43_NPHY_TXPCTL_BIDX_LOAD | nphy->txpctl_bidx);
     +		nphy->txpctl_bidx_loaded = true;
    -+		nphy->txpctl_last_sample = now;
    -+	} else if (nphy->txpctl_bidx_loaded) {
    -+		if (time_after(now, nphy->txpctl_last_sample + HZ / 50)) {
    -+			b43_phy_write(dev, B43_NPHY_TXPCTL_BIDX,
    -+				      nphy->txpctl_bidx);
    -+			nphy->txpctl_bidx_loaded = false;
    -+			nphy->txpctl_last_sample = now;
    -+		}
    -+	} else if (time_before(now, nphy->txpctl_last_tx + HZ / 20) &&
    -+		   (!nphy->txpctl_bidx_valid ||
    -+		    time_after(now, nphy->txpctl_last_sample + HZ / 5))) {
    ++	} else if (unload) {
    ++		b43_phy_write(dev, B43_NPHY_TXPCTL_BIDX, nphy->txpctl_bidx);
    ++		nphy->txpctl_bidx_loaded = false;
    ++	} else {
     +		c1 = b43_phy_read(dev, B43_NPHY_C1_TXPCTL_STAT);
     +		c2 = b43_phy_read(dev, B43_NPHY_C2_TXPCTL_STAT);
     +		nphy->txpctl_bidx = (c1 & B43_NPHY_TXPCTL_STAT_BIDX) >>
     +				    B43_NPHY_TXPCTL_STAT_BIDX_SHIFT;
     +		nphy->txpctl_bidx |= c2 & B43_NPHY_TXPCTL_STAT_BIDX;
     +		nphy->txpctl_bidx_valid = true;
    -+		nphy->txpctl_last_sample = now;
     +	}
     +
    -+	nphy->txpctl_last_tx = now;
    ++	if (nphy->hang_avoid)
    ++		b43_nphy_stay_in_carrier_search(dev, 0);
    ++	b43_mac_enable(dev);
    ++
    ++	nphy->txpctl_last_sample = now;
     +}
     +
      /* https://bcm-v4.sipsolutions.net/802.11/PHY/N/SetChanspec */
    @@ drivers/net/wireless/broadcom/b43/phy_n.c: static int b43_nphy_set_channel(struc
      	/* Channel is set later in common code, but we need to set it on our
      	   own to let this function's subcalls work properly. */
      	phy->channel = channel->hw_value;
    -+	dev->phy.n->txpctl_bidx_valid = false;
    -+	if (dev->phy.n->txpctl_bidx_loaded) {
    -+		b43_phy_write(dev, B43_NPHY_TXPCTL_BIDX, 0);
    -+		dev->phy.n->txpctl_bidx_loaded = false;
    -+	}
    ++	b43_nphy_txpctl_bidx_reset(dev);
      
      #if 0
      	if (b43_channel_type_is_40mhz(phy->channel_type) !=
    @@ drivers/net/wireless/broadcom/b43/phy_n.h: struct b43_phy_n {
      struct b43_phy_operations;
      extern const struct b43_phy_operations b43_phyops_n;
      
    ++#ifdef CONFIG_B43_PHY_N
     +void b43_nphy_txpctl_ofdm_tx(struct b43_wldev *dev);
    ++#else
    ++static inline void b43_nphy_txpctl_ofdm_tx(struct b43_wldev *dev)
    ++{
    ++}
    ++#endif
     +
      #endif /* B43_NPHY_H_ */