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authorMohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>2012-06-18 13:13:30 +0530
committerJohn W. Linville <linville@tuxdriver.com>2012-06-20 14:10:25 -0400
commitf18e3c6b67f448ec47b3a5b242789bd3d5644879 (patch)
tree5b5b7482806789afd92a9369fe4697e67046132f
parenta859e4d6590b2429f518aa712b9e3edd367398d7 (diff)
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ath9k_hw: avoid possible infinite loop in ar9003_get_pll_sqsum_dvc
"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: stable@vger.kernel.org Cc: Rolf Offermanns <rolf.offermanns@gmx.net> Cc: Sujith Manoharan <c_manoha@qca.qualcomm.com> Cc: Senthil Balasubramanian <senthilb@qca.qualcomm.com> Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
-rw-r--r--drivers/net/wireless/ath/ath9k/hw.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 7db1890448f2..1c68e564f503 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);