From 43f88d530ec656d9b556fb0d127b30757b1c3d35 Mon Sep 17 00:00:00 2001 From: Daniel Lichtenberger Date: Thu, 28 Oct 2010 23:20:12 +0200 Subject: [PATCH] Staging: rtl8192e: fix IOMMU memory leak Unmap the rx buffer before mapping the new one in rtl8192_rx. Failing to do so quickly exhausts the IOMMU memory during downloads: [...] DMA: Out of SW-IOMMU space for 9100 bytes at device ... Using "iommu=off mem=4g" also fixes the problem because then pci_map_single does not allocate memory. Tested on my personal laptop with a RTL8192E device. Without this patch the kernel quickly runs out of IOMMU memory (downloading 5 MB of data is sufficient to trigger it), with this patch applied I haven't experienced any issues so far. Signed-off-by: Daniel Lichtenberger Signed-off-by: Greg Kroah-Hartman --- drivers/staging/rtl8192e/r8192E_core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/staging/rtl8192e/r8192E_core.c b/drivers/staging/rtl8192e/r8192E_core.c index a202194b5cbb..b1786dcac245 100644 --- a/drivers/staging/rtl8192e/r8192E_core.c +++ b/drivers/staging/rtl8192e/r8192E_core.c @@ -5829,6 +5829,9 @@ static void rtl8192_rx(struct net_device *dev) } } + pci_unmap_single(priv->pdev, *((dma_addr_t *) skb->cb), + priv->rxbuffersize, PCI_DMA_FROMDEVICE); + skb = new_skb; priv->rx_buf[priv->rx_idx] = skb; *((dma_addr_t *) skb->cb) = pci_map_single(priv->pdev, skb_tail_pointer(skb), priv->rxbuffersize, PCI_DMA_FROMDEVICE);