On 2011-04-08 7:17 PM, John W. Linville wrote:
On Fri, Apr 08, 2011 at 02:06:55PM +0200, Felix Fietkau wrote:During PHY errors, the MAC can sometimes fail to enter an idle state on older hardware (before AR9380) after an rx stop has been requested. This typically shows up in the kernel log with messages like these: ath: Could not stop RX, we could be confusing the DMA engine when we start RX up ------------[ cut here ]------------ WARNING: at drivers/net/wireless/ath/ath9k/recv.c:504 ath_stoprecv+0xcc/0xf0 [ath9k]() Call Trace: [<8023f0e8>] dump_stack+0x8/0x34 [<80075050>] warn_slowpath_common+0x78/0xa4 [<80075094>] warn_slowpath_null+0x18/0x24 [<80d66d60>] ath_stoprecv+0xcc/0xf0 [ath9k] [<80d642cc>] ath_set_channel+0xbc/0x270 [ath9k] [<80d65254>] ath_radio_disable+0x4a4/0x7fc [ath9k] When this happens, the state that the MAC enters is easy to identify and does not result in bogus DMA traffic, however to ensure a working state after a channel change, the hardware should still be reset. This patch adds detection for this specific MAC state, after which the above warnings completely disappear in my tests. Signed-off-by: Felix Fietkau<nbd@xxxxxxxxxxx> Cc: stable@xxxxxxxxxx Cc: Kyungwan Nam<Kyungwan.Nam@xxxxxxxxxxx> --- v2: remove a redundant ath9k_hw_stopdmarecv call, print the MAC DMA state when the error still occurs drivers/net/wireless/ath/ath9k/hw.c | 9 --------- drivers/net/wireless/ath/ath9k/mac.c | 25 ++++++++++++++++++++++--- drivers/net/wireless/ath/ath9k/mac.h | 2 +- drivers/net/wireless/ath/ath9k/recv.c | 6 +++--- 4 files changed, 26 insertions(+), 16 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c index 1b5bd13..c8a2d0d 100644 --- a/drivers/net/wireless/ath/ath9k/hw.c +++ b/drivers/net/wireless/ath/ath9k/hw.c @@ -1249,15 +1249,6 @@ int ath9k_hw_reset(struct ath_hw *ah, struct ath9k_channel *chan, ah->txchainmask = common->tx_chainmask; ah->rxchainmask = common->rx_chainmask; - if ((common->bus_ops->ath_bus_type != ATH_USB)&& !ah->chip_fullsleep) {This patch seems a bit busted...? I tried to fix it up manually but the errors just keep coming...
Hm, you're right. No idea what my email client did there. I'll resend... - Felix -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
