ath9k: fix some issues in PA predistortion (still disabled by default)

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36744 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/mac80211/patches/300-pending_work.patch

@@ -4570,3 +4570,44 @@
  		return -EINVAL;
  
  	trace_drv_add_interface(local, sdata);
+--- a/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
++++ b/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
+@@ -454,6 +454,8 @@ static bool create_pa_curve(u32 *data_L,
+ 		if (accum_cnt <= thresh_accum_cnt)
+ 			continue;
+ 
++		max_index++;
++
+ 		/* sum(tx amplitude) */
+ 		accum_tx = ((data_L[i] >> 16) & 0xffff) |
+ 		    ((data_U[i] & 0x7ff) << 16);
+@@ -468,20 +470,21 @@ static bool create_pa_curve(u32 *data_L,
+ 
+ 		accum_tx <<= scale_factor;
+ 		accum_rx <<= scale_factor;
+-		x_est[i + 1] = (((accum_tx + accum_cnt) / accum_cnt) + 32) >>
+-		    scale_factor;
++		x_est[max_index] =
++			(((accum_tx + accum_cnt) / accum_cnt) + 32) >>
++			scale_factor;
+ 
+-		Y[i + 1] = ((((accum_rx + accum_cnt) / accum_cnt) + 32) >>
++		Y[max_index] =
++			((((accum_rx + accum_cnt) / accum_cnt) + 32) >>
+ 			    scale_factor) +
+-			    (1 << scale_factor) * max_index + 16;
++			(1 << scale_factor) * i + 16;
+ 
+ 		if (accum_ang >= (1 << 26))
+ 			accum_ang -= 1 << 27;
+ 
+-		theta[i + 1] = ((accum_ang * (1 << scale_factor)) + accum_cnt) /
+-		    accum_cnt;
+-
+-		max_index++;
++		theta[max_index] =
++			((accum_ang * (1 << scale_factor)) + accum_cnt) /
++			accum_cnt;
+ 	}
+ 
+ 	/*