Is this a fix for 3.10? Should it go to stable? On Tue, May 28, 2013 at 06:04:44PM +0200, Felix Fietkau wrote: > If any bins from the training data are skipped (i != max_index), the > calculated compensation curve gets distorted, and the signal will be > wildly overamplified. This may be the cause of the reported hardware > damage that was caused by PA predistortion (because of which PAPRD was > disabled by default). > > When calculating the x_est, Y, theta values, the use of max_index and i > was reversed. i points to the bin index whereas max_index refers to the > index of the calculated arrays. > > Note that PA predistortion is still disabled, it will be re-enabled > after it has been properly validated. > > Signed-off-by: Felix Fietkau <nbd@xxxxxxxxxxx> > --- > drivers/net/wireless/ath/ath9k/ar9003_paprd.c | 19 +++++++++++-------- > 1 file changed, 11 insertions(+), 8 deletions(-) > > diff --git a/drivers/net/wireless/ath/ath9k/ar9003_paprd.c b/drivers/net/wireless/ath/ath9k/ar9003_paprd.c > index 09c1f9d..6343cc9 100644 > --- 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, u32 *data_U, u32 *pa_table, u16 *gain) > 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, u32 *data_U, u32 *pa_table, u16 *gain) > > 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; > } > > /* > -- > 1.8.0.2 > > -- John W. Linville Someday the world will need a hero, and you linville@xxxxxxxxxxxxx might be all we have. Be ready. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
