rtlwifi: Add missing DMA buffer unmapping for PCI drivers
In https://bugzilla.kernel.org/show_bug.cgi?id=42976, a system with driver
rtl8192se used as an AP suffers from "Out of SW-IOMMU space" errors. These
are caused by the DMA buffers used for beacons never being unmapped.
This bug was also reported at
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/961618
Reported-and-Tested-by: Da Xue <da@lessconfused.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rtlwifi/pci.c b/drivers/net/wireless/rtlwifi/pci.c
index 07dd38e..288b035 100644
--- a/drivers/net/wireless/rtlwifi/pci.c
+++ b/drivers/net/wireless/rtlwifi/pci.c
@@ -912,8 +912,13 @@
memset(&tcb_desc, 0, sizeof(struct rtl_tcb_desc));
ring = &rtlpci->tx_ring[BEACON_QUEUE];
pskb = __skb_dequeue(&ring->queue);
- if (pskb)
+ if (pskb) {
+ struct rtl_tx_desc *entry = &ring->desc[ring->idx];
+ pci_unmap_single(rtlpci->pdev, rtlpriv->cfg->ops->get_desc(
+ (u8 *) entry, true, HW_DESC_TXBUFF_ADDR),
+ pskb->len, PCI_DMA_TODEVICE);
kfree_skb(pskb);
+ }
/*NB: the beacon data buffer must be 32-bit aligned. */
pskb = ieee80211_beacon_get(hw, mac->vif);