From 673f7786e205c87b5d978c62827b9a66d097bebb Mon Sep 17 00:00:00 2001 From: Larry Finger Date: Mon, 26 Mar 2012 10:48:20 -0500 Subject: [PATCH] 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 Signed-off-by: Larry Finger Cc: Stable Signed-off-by: John W. Linville --- drivers/net/wireless/rtlwifi/pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/rtlwifi/pci.c b/drivers/net/wireless/rtlwifi/pci.c index 07dd38efe62a..288b035a3579 100644 --- a/drivers/net/wireless/rtlwifi/pci.c +++ b/drivers/net/wireless/rtlwifi/pci.c @@ -912,8 +912,13 @@ static void _rtl_pci_prepare_bcn_tasklet(struct ieee80211_hw *hw) 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);