[16/38] ath9k_hw: prevent a fast channel change after a rx DMA stuck issue

From: Greg KH
Date: Fri Aug 06 2010 - 14:35:56 EST

2.6.35-stable review patch. If anyone has any objections, please let us know.


From: Felix Fietkau <nbd@xxxxxxxxxxx>

commit 9cc2f3e881dcda5466c55ffe8dd0a9d1433469cb upstream.

If the receive path gets stuck, a full hardware reset is necessary to
recover from it. If this happens during a scan, the whole scan might fail,
as each channel change bypasses the full reset sequence.
Fix this by resetting the fast channel change flag if stopping the
receive path fails.

This will reduce the number of error messages that look like this:
ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x40000020

Signed-off-by: Felix Fietkau <nbd@xxxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

drivers/net/wireless/ath/ath9k/hw.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1233,9 +1233,11 @@ int ath9k_hw_reset(struct ath_hw *ah, st

if (!ah->chip_fullsleep) {
- if (!ath9k_hw_stopdmarecv(ah))
+ if (!ath9k_hw_stopdmarecv(ah)) {
ath_print(common, ATH_DBG_XMIT,
"Failed to stop receive dma\n");
+ bChannelChange = false;
+ }

if (!ath9k_hw_setpower(ah, ATH9K_PM_AWAKE))

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