3.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mohammed Shafi Shajakhan <[email protected]>

commit f18e3c6b67f448ec47b3a5b242789bd3d5644879 upstream.

"ath9k: Fix softlockup in AR9485" with commit id
64bc1239c790e051ff677e023435d770d2ffa174 fixed the reported
issue, yet its better to avoid the possible infinite loop
in ar9003_get_pll_sqsum_dvc by having a timeout as suggested
by ath9k maintainers.
http://www.spinics.net/lists/linux-wireless/msg92126.html.
Based on my testing PLL's locking measurement is done in
~200us (2 iterations).

Cc: Rolf Offermanns <[email protected]>
Cc: Sujith Manoharan <[email protected]>
Cc: Senthil Balasubramanian <[email protected]>
Signed-off-by: Mohammed Shafi Shajakhan <[email protected]>
Signed-off-by: John W. Linville <[email protected]>
Signed-off-by: Ben Hutchings <[email protected]>
---
 drivers/net/wireless/ath/ath9k/hw.c |   14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath9k/hw.c 
b/drivers/net/wireless/ath/ath9k/hw.c
index 7db1890..1c68e56 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -784,13 +784,25 @@ static void ath9k_hw_init_qos(struct ath_hw *ah)
 
 u32 ar9003_get_pll_sqsum_dvc(struct ath_hw *ah)
 {
+       struct ath_common *common = ath9k_hw_common(ah);
+       int i = 0;
+
        REG_CLR_BIT(ah, PLL3, PLL3_DO_MEAS_MASK);
        udelay(100);
        REG_SET_BIT(ah, PLL3, PLL3_DO_MEAS_MASK);
 
-       while ((REG_READ(ah, PLL4) & PLL4_MEAS_DONE) == 0)
+       while ((REG_READ(ah, PLL4) & PLL4_MEAS_DONE) == 0) {
+
                udelay(100);
 
+               if (WARN_ON_ONCE(i >= 100)) {
+                       ath_err(common, "PLL4 meaurement not done\n");
+                       break;
+               }
+
+               i++;
+       }
+
        return (REG_READ(ah, PLL3) & SQSUM_DVC_MASK) >> 3;
 }
 EXPORT_SYMBOL(ar9003_get_pll_sqsum_dvc);


--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to