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Commit 43f88d53 authored by Daniel Lichtenberger's avatar Daniel Lichtenberger Committed by Greg Kroah-Hartman
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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: default avatarDaniel Lichtenberger <daniel.lichtenberger@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent eacd121c

drivers/staging/rtl8192e/r8192E_core.c

+3 −0
Original line number Diff line number Diff line
@@ -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);