1 files changed, 19 insertions, 18 deletions

diff --git a/drivers/net/wireless/ath/ath5k/phy.c b/drivers/net/wireless/ath/ath5k/phy.c
index ffe253ab9be7..eff3323efb4b 100644
--- a/drivers/net/wireless/ath/ath5k/phy.c
+++ b/drivers/net/wireless/ath/ath5k/phy.c
@@ -1386,38 +1386,39 @@ static int ath5k_hw_rf511x_calibrate(struct ath5k_hw *ah,
                 goto done;
 
         /* Calibration has finished, get the results and re-run */
+
+        /* work around empty results which can apparently happen on 5212 */
         for (i = 0; i <= 10; i++) {
                 iq_corr = ath5k_hw_reg_read(ah, AR5K_PHY_IQRES_CAL_CORR);
                 i_pwr = ath5k_hw_reg_read(ah, AR5K_PHY_IQRES_CAL_PWR_I);
                 q_pwr = ath5k_hw_reg_read(ah, AR5K_PHY_IQRES_CAL_PWR_Q);
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_CALIBRATE,
+                        "iq_corr:%x i_pwr:%x q_pwr:%x", iq_corr, i_pwr, q_pwr);
+                if (i_pwr && q_pwr)
+                        break;
         }
 
         i_coffd = ((i_pwr >> 1) + (q_pwr >> 1)) >> 7;
         q_coffd = q_pwr >> 7;
 
-        /* No correction */
-        if (i_coffd == 0 || q_coffd == 0)
+        /* protect against divide by 0 and loss of sign bits */
+        if (i_coffd == 0 || q_coffd < 2)
                 goto done;
 
-        i_coff = ((-iq_corr) / i_coffd);
+        i_coff = (-iq_corr) / i_coffd;
+        i_coff = clamp(i_coff, -32, 31); /* signed 6 bit */
 
-        /* Boundary check */
-        if (i_coff > 31)
-                i_coff = 31;
-        if (i_coff < -32)
-                i_coff = -32;
+        q_coff = (i_pwr / q_coffd) - 128;
+        q_coff = clamp(q_coff, -16, 15); /* signed 5 bit */
 
-        q_coff = (((s32)i_pwr / q_coffd) - 128);
+        ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_CALIBRATE,
+                        "new I:%d Q:%d (i_coffd:%x q_coffd:%x)",
+                        i_coff, q_coff, i_coffd, q_coffd);
 
-        /* Boundary check */
-        if (q_coff > 15)
-                q_coff = 15;
-        if (q_coff < -16)
-                q_coff = -16;
-
-        /* Commit new I/Q value */
-        AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_IQ, AR5K_PHY_IQ_CORR_ENABLE |
-                ((u32)q_coff) | ((u32)i_coff << AR5K_PHY_IQ_CORR_Q_I_COFF_S));
+        /* Commit new I/Q values (set enable bit last to match HAL sources) */
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_IQ, AR5K_PHY_IQ_CORR_Q_I_COFF, i_coff);
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_IQ, AR5K_PHY_IQ_CORR_Q_Q_COFF, q_coff);
+        AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_IQ, AR5K_PHY_IQ_CORR_ENABLE);
 
         /* Re-enable calibration -if we don't we'll commit
          * the same values again and again */