Some cards don't update the PISR properly when all SISR bits
for Tx interrupts are being cleared and as a result we get
interrupt storm. Since we handle all tx queues all together
(so we don't really use the SISR bits to do per-queue interrupt
handling), we can manualy update PISR by doing a write-to-clear
on its Tx interrupt bits.
Signed-off-by: Nick Kossifidis <[email protected]>
---
drivers/net/wireless/ath/ath5k/dma.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/ath/ath5k/dma.c b/drivers/net/wireless/ath/ath5k/dma.c
index ce86f15..84c01c5 100644
--- a/drivers/net/wireless/ath/ath5k/dma.c
+++ b/drivers/net/wireless/ath/ath5k/dma.c
@@ -616,7 +616,16 @@ ath5k_hw_get_isr(struct ath5k_hw *ah, enum ath5k_int *interrupt_mask)
* SISRs will also clear PISR so no need to worry here.
*/
- pisr_clear = pisr & ~AR5K_ISR_BITS_FROM_SISRS;
+ /* XXX: There seems to be an issue on some cards
+ * with tx interrupt flags not being updated
+ * on PISR despite that all Tx interrupt bits
+ * are cleared on SISRs. Since we handle all
+ * Tx queues all together it shouldn't be an
+ * issue if we clear Tx interrupt flags also
+ * on PISR to avoid that.
+ */
+ pisr_clear = (pisr & ~AR5K_ISR_BITS_FROM_SISRS) |
+ (pisr & AR5K_INT_TX_ALL);
/*
* Write to clear them...
--
1.8.4.4