ath9k: Fix a dma warning/memory leak

proper dma_unmapping and freeing of skb's has to be done in the rx cleanup for EDMA chipsets when the device is unloaded and this also seems to address the following warning which shows up occasionally when the device is unloaded	Call Trace:	[<c0148cd2>] warn_slowpath_common+0x72/0xa0	[<c03b669c>] ? dma_debug_device_change+0x19c/0x200	[<c03b669c>] ? dma_debug_device_change+0x19c/0x200	[<c0148da3>] warn_slowpath_fmt+0x33/0x40	[<c03b669c>] dma_debug_device_change+0x19c/0x200	[<c0657f12>] notifier_call_chain+0x82/0xb0	[<c0171370>] __blocking_notifier_call_chain+0x60/0x90	[<c01713bf>] blocking_notifier_call_chain+0x1f/0x30	[<c044f594>] __device_release_driver+0xa4/0xc0	[<c044f647>] driver_detach+0x97/0xa0	[<c044e65c>] bus_remove_driver+0x6c/0xe0	[<c029af0b>] ? sysfs_addrm_finish+0x4b/0x60	[<c0450109>] driver_unregister+0x49/0x80	[<c0299f54>] ? sysfs_remove_file+0x14/0x20	[<c03c3ab2>] pci_unregister_driver+0x32/0x80	[<f92c2162>] ath_pci_exit+0x12/0x20 [ath9k]	[<f92c8467>] ath9k_exit+0x17/0x36 [ath9k]	[<c06523cd>] ? mutex_unlock+0xd/0x10	[<c018e27f>] sys_delete_module+0x13f/0x200	[<c02139bb>] ? sys_munmap+0x4b/0x60	[<c06547c5>] ? restore_all+0xf/0xf	[<c0657a20>] ? spurious_fault+0xe0/0xe0	[<c01832f4>] ? trace_hardirqs_on_caller+0xf4/0x180	[<c065b863>] sysenter_do_call+0x12/0x38 ---[ end trace 16e1c1521c06bcf9 ]---	Mapped at:	[<c03b7938>] debug_dma_map_page+0x48/0x120	[<f92ba3e8>] ath_rx_init+0x3f8/0x4b0 [ath9k]	[<f92b5ae4>] ath9k_init_device+0x4c4/0x7b0 [ath9k]	[<f92c2813>] ath_pci_probe+0x263/0x330 [ath9k] Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>

Author: Mohammed Shafi Shajakhan

drivers/net/wireless/ath/ath9k/recv.c

@@ -205,14 +205,22 @@ static void ath_rx_remove_buffer(struct ath_softc *sc,
 
 static void ath_rx_edma_cleanup(struct ath_softc *sc)
 {
+struct ath_hw *ah = sc->sc_ah;
+struct ath_common *common = ath9k_hw_common(ah);
 struct ath_buf *bf;
 
 ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
 ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
 
 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
-if (bf->bf_mpdu)
+if (bf->bf_mpdu) {
+dma_unmap_single(sc->dev, bf->bf_buf_addr,
+common->rx_bufsize,
+DMA_BIDIRECTIONAL);
 dev_kfree_skb_any(bf->bf_mpdu);
+bf->bf_buf_addr = 0;
+bf->bf_mpdu = NULL;
+}
 }
 
 INIT_LIST_HEAD(&sc->rx.rxbuf);