ath5k: treat RXORN as non-fatal

We get RXORN interrupts when all receive buffers are full. This is not
necessarily a fatal situation. It can also happen when the bus is busy or the
CPU is not fast enough to process all frames.

Older chipsets apparently need a reset to come out of this situration, but on
newer chips we can treat RXORN like RX, as going thru a full reset does more
harm than good, there.

The exact chip revisions which need a reset are unknown - this guess
AR5K_SREV_AR5212 ("venice") is copied from the HAL.

Inspired by openwrt 413-rxorn.patch:
"treat rxorn like rx, reset after rxorn seems to do more harm than good"

Signed-off-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/base.c

@@ -2705,7 +2705,20 @@ ath5k_intr(int irq, void *dev_id)
 			 */
 			tasklet_schedule(&sc->restq);
 		} else if (unlikely(status & AR5K_INT_RXORN)) {
-			tasklet_schedule(&sc->restq);
+			/*
+			 * Receive buffers are full. Either the bus is busy or
+			 * the CPU is not fast enough to process all received
+			 * frames.
+			 * Older chipsets need a reset to come out of this
+			 * condition, but we treat it as RX for newer chips.
+			 * We don't know exactly which versions need a reset -
+			 * this guess is copied from the HAL.
+			 */
+			sc->stats.rxorn_intr++;
+			if (ah->ah_mac_srev < AR5K_SREV_AR5212)
+				tasklet_schedule(&sc->restq);
+			else
+				tasklet_schedule(&sc->rxtq);
 		} else {
 			if (status & AR5K_INT_SWBA) {
 				tasklet_hi_schedule(&sc->beacontq);

drivers/net/wireless/ath/ath5k/base.h

@@ -135,6 +135,7 @@ struct ath5k_statistics {
 	unsigned int beacons;
 
 	unsigned int mib_intr;
+	unsigned int rxorn_intr;
 };
 
 #if CHAN_DEBUG