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 <daniel.lichtenberger@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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