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Commit 2d3fca18 authored by Senthil Balasubramanian's avatar Senthil Balasubramanian Committed by John W. Linville
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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: default avatarSenthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 0dfa6dbb

drivers/net/wireless/ath/ath9k/ar9003_paprd.c

+9 −5
Original line number Diff line number Diff line
@@ -347,6 +347,10 @@ static bool create_pa_curve(u32 *data_L, u32 *data_U, u32 *pa_table, u16 *gain) 
	    (((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 @@ static bool create_pa_curve(u32 *data_L, u32 *data_U, u32 *pa_table, u16 *gain) 


	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 @@ static bool create_pa_curve(u32 *data_L, u32 *data_U, u32 *pa_table, u16 *gain) 


	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);