2014-01-14 08:00:37

by Sujith Manoharan

Subject: [PATCH] ath9k: Fix IQ calibration

From: Sujith Manoharan <[email protected]>

This patch fixes a bug in the TX IQ calibration post
processing routine because of which the driver disables
TX IQ correction even though the calibration results
are valid. This fix is applicable for all chips in the
AR9003 family.

Signed-off-by: Sujith Manoharan <[email protected]>
---
drivers/net/wireless/ath/ath9k/ar9003_calib.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_calib.c b/drivers/net/wireless/ath/ath9k/ar9003_calib.c
index 8c145cd..4eb35aa 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_calib.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_calib.c
@@ -655,8 +655,8 @@ static bool ar9003_hw_calc_iq_corr(struct ath_hw *ah,
if (i2_m_q2_a0_d1 > 0x800)
i2_m_q2_a0_d1 = -((0xfff - i2_m_q2_a0_d1) + 1);

- if (i2_p_q2_a0_d1 > 0x800)
- i2_p_q2_a0_d1 = -((0xfff - i2_p_q2_a0_d1) + 1);
+ if (i2_p_q2_a0_d1 > 0x1000)
+ i2_p_q2_a0_d1 = -((0x1fff - i2_p_q2_a0_d1) + 1);

if (iq_corr_a0_d1 > 0x800)
iq_corr_a0_d1 = -((0xfff - iq_corr_a0_d1) + 1);
@@ -700,6 +700,19 @@ static bool ar9003_hw_calc_iq_corr(struct ath_hw *ah,
return false;
}

+ if ((i2_p_q2_a0_d0 < 1024) || (i2_p_q2_a0_d0 > 2047) ||
+ (i2_p_q2_a1_d0 < 0) || (i2_p_q2_a1_d1 < 0) ||
+ (i2_p_q2_a0_d0 <= i2_m_q2_a0_d0) ||
+ (i2_p_q2_a0_d0 <= iq_corr_a0_d0) ||
+ (i2_p_q2_a0_d1 <= i2_m_q2_a0_d1) ||
+ (i2_p_q2_a0_d1 <= iq_corr_a0_d1) ||
+ (i2_p_q2_a1_d0 <= i2_m_q2_a1_d0) ||
+ (i2_p_q2_a1_d0 <= iq_corr_a1_d0) ||
+ (i2_p_q2_a1_d1 <= i2_m_q2_a1_d1) ||
+ (i2_p_q2_a1_d1 <= iq_corr_a1_d1)) {
+ return false;
+ }
+
mag_a0_d0 = (i2_m_q2_a0_d0 * res_scale) / i2_p_q2_a0_d0;
phs_a0_d0 = (iq_corr_a0_d0 * res_scale) / i2_p_q2_a0_d0;

--
1.8.5.2

2014-01-20 06:02:41

by Alex Hacker

Subject: Re: [ath9k-devel] [PATCH] ath9k: Fix IQ calibration

Hello,

On Tue, Jan 14, 2014 at 01:25:17PM +0530, Sujith Manoharan wrote:
> + if (i2_p_q2_a0_d1 > 0x1000)
> + i2_p_q2_a0_d1 = -((0x1fff - i2_p_q2_a0_d1) + 1);

While the 'i2_p_q2_a0_d1 = (iq_res[2] & 0xfff)' the condition
'i2_p_q2_a0_d1 > 0x1000' is always false.

Regards,
Alex.

2014-01-20 06:49:53

by Sujith Manoharan

Subject: Re: [ath9k-devel] [PATCH] ath9k: Fix IQ calibration

Alex Hacker wrote:
> While the 'i2_p_q2_a0_d1 = (iq_res[2] & 0xfff)' the condition
> 'i2_p_q2_a0_d1 > 0x1000' is always false.

You are correct. I'll check with the systems engineers if something else
is missing. Thanks !

Sujith