ath9k_hw: Fix divide by zero cases in paprd.
We are not handling all divide by zero cases in paprd.
Add additional checks for divide by zero cases in papard.
This patch has fixes intended for kernel 2.6.36.
Cc: stable@kernel.org
Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/ar9003_paprd.c b/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
index 7c38229..716db41 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
@@ -347,6 +347,10 @@
(((Y[6] - Y[3]) * 1 << scale_factor) +
(x_est[6] - x_est[3])) / (x_est[6] - x_est[3]);
+ /* prevent division by zero */
+ if (G_fxp == 0)
+ return false;
+
Y_intercept =
(G_fxp * (x_est[0] - x_est[3]) +
(1 << scale_factor)) / (1 << scale_factor) + Y[3];
@@ -356,14 +360,12 @@
for (i = 0; i <= 3; i++) {
y_est[i] = i * 32;
-
- /* prevent division by zero */
- if (G_fxp == 0)
- return false;
-
x_est[i] = ((y_est[i] * 1 << scale_factor) + G_fxp) / G_fxp;
}
+ if (y_est[max_index] == 0)
+ return false;
+
x_est_fxp1_nonlin =
x_est[max_index] - ((1 << scale_factor) * y_est[max_index] +
G_fxp) / G_fxp;
@@ -457,6 +459,8 @@
Q_scale_B = find_proper_scale(find_expn(abs(scale_B)), 10);
scale_B = scale_B / (1 << Q_scale_B);
+ if (scale_B == 0)
+ return false;
Q_beta = find_proper_scale(find_expn(abs(beta_raw)), 10);
Q_alpha = find_proper_scale(find_expn(abs(alpha_raw)), 10);
beta_raw = beta_raw / (1 << Q_beta);