While 32 KHz sleep clock might provide some power saving benefits,
it is also a major source of stability issues, on OpenWrt it produced
some reproducible data bus errors on register accesses on several
different MIPS platforms.
All the Atheros drivers that I can find do not enable this feature,
so it makes sense to leave it disabled in ath5k as well.
Signed-off-by: Felix Fietkau <nbd@xxxxxxxxxxx>
Acked-by: Nick Kossifidis <mickflemm@xxxxxxxxx>
---
drivers/net/wireless/ath/ath5k/ath5k.h | 2 ++
drivers/net/wireless/ath/ath5k/debug.c | 3 +++
drivers/net/wireless/ath/ath5k/reset.c | 11 ++++++++---
3 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/ath/ath5k/ath5k.h b/drivers/net/wireless/ath/ath5k/ath5k.h
index 50d7580..8ff1794 100644
--- a/drivers/net/wireless/ath/ath5k/ath5k.h
+++ b/drivers/net/wireless/ath/ath5k/ath5k.h
@@ -1067,6 +1067,8 @@ struct ath5k_hw {
u8 ah_retry_long;
u8 ah_retry_short;
+ u32 ah_use_32khz_clock;
+
u8 ah_coverage_class;
bool ah_ack_bitrate_high;
u8 ah_bwmode;
diff --git a/drivers/net/wireless/ath/ath5k/debug.c b/drivers/net/wireless/ath/ath5k/debug.c
index ae1112b..4edca70 100644
--- a/drivers/net/wireless/ath/ath5k/debug.c
+++ b/drivers/net/wireless/ath/ath5k/debug.c
@@ -922,6 +922,9 @@ ath5k_debug_init_device(struct ath5k_softc *sc)
debugfs_create_file("queue", S_IWUSR | S_IRUSR, phydir, sc,
&fops_queue);
+
+ debugfs_create_bool("32khz_clock", S_IWUSR | S_IRUSR, phydir,
+ &sc->ah->ah_use_32khz_clock);
}
/* functions used in other places */
diff --git a/drivers/net/wireless/ath/ath5k/reset.c b/drivers/net/wireless/ath/ath5k/reset.c
index 0e89fc9..9f9c2ad 100644
--- a/drivers/net/wireless/ath/ath5k/reset.c
+++ b/drivers/net/wireless/ath/ath5k/reset.c
@@ -1287,11 +1287,16 @@ int ath5k_hw_reset(struct ath5k_hw *ah, enum nl80211_iftype op_mode,
ath5k_hw_dma_init(ah);
- /* Enable 32KHz clock function for AR5212+ chips
+ /*
+ * Enable 32KHz clock function for AR5212+ chips
* Set clocks to 32KHz operation and use an
* external 32KHz crystal when sleeping if one
- * exists */
- if (ah->ah_version == AR5K_AR5212 &&
+ * exists.
+ * Disabled by default because it is also disabled in
+ * other drivers and it is known to cause stability
+ * issues on some devices
+ */
+ if (ah->ah_use_32khz_clock && ah->ah_version == AR5K_AR5212 &&
op_mode != NL80211_IFTYPE_AP)
ath5k_hw_set_sleep_clock(ah, true);
--
1.7.3.2
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