ath9k: fix stopping tx dma on reset
In some situations, stopping Tx DMA frequently fails, leading to messages
like this:
ath: Failed to stop TX DMA in 100 msec after killing last frame
ath: Failed to stop TX DMA!
This patch uses a few MAC features to abort DMA globally instead of iterating
over all hardware queues and attempting to stop them individually.
Not only is that faster and works with a shorter timeout, it also makes the
process much more reliable.
With this change, I can no longer trigger these messages on AR9380,
and on AR9280 they become much more rare.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/mac.c b/drivers/net/wireless/ath/ath9k/mac.c
index c75d40f..58aaf9a 100644
--- a/drivers/net/wireless/ath/ath9k/mac.c
+++ b/drivers/net/wireless/ath/ath9k/mac.c
@@ -143,6 +143,34 @@
}
EXPORT_SYMBOL(ath9k_hw_updatetxtriglevel);
+void ath9k_hw_abort_tx_dma(struct ath_hw *ah)
+{
+ int i, q;
+
+ REG_WRITE(ah, AR_Q_TXD, AR_Q_TXD_M);
+
+ REG_SET_BIT(ah, AR_PCU_MISC, AR_PCU_FORCE_QUIET_COLL | AR_PCU_CLEAR_VMF);
+ REG_SET_BIT(ah, AR_DIAG_SW, AR_DIAG_FORCE_CH_IDLE_HIGH);
+ REG_SET_BIT(ah, AR_D_GBL_IFS_MISC, AR_D_GBL_IFS_MISC_IGNORE_BACKOFF);
+
+ for (q = 0; q < AR_NUM_QCU; q++) {
+ for (i = 0; i < 1000; i++) {
+ if (i)
+ udelay(5);
+
+ if (!ath9k_hw_numtxpending(ah, q))
+ break;
+ }
+ }
+
+ REG_CLR_BIT(ah, AR_PCU_MISC, AR_PCU_FORCE_QUIET_COLL | AR_PCU_CLEAR_VMF);
+ REG_CLR_BIT(ah, AR_DIAG_SW, AR_DIAG_FORCE_CH_IDLE_HIGH);
+ REG_CLR_BIT(ah, AR_D_GBL_IFS_MISC, AR_D_GBL_IFS_MISC_IGNORE_BACKOFF);
+
+ REG_WRITE(ah, AR_Q_TXD, 0);
+}
+EXPORT_SYMBOL(ath9k_hw_abort_tx_dma);
+
bool ath9k_hw_stoptxdma(struct ath_hw *ah, u32 q)
{
#define ATH9K_TX_STOP_DMA_TIMEOUT 4000 /* usec */