package/kernel/mac80211/patches/330-ath10k-wmi-alloc-chunk-should-use-DMA_BIDIRECTIONAL.patch

   1 From: Ben Greear <greearb@candelatech.com>
   2 Date: Tue, 29 Nov 2016 14:00:28 -0800
   3 Subject: [PATCH] ath10k: wmi-alloc-chunk should use DMA_BIDIRECTIONAL.
   4
   5 These memory chunks are often used as 'swap' by the NIC,
   6 so it will be both reading and writing to these areas.
   7
   8 This seems to fix errors like this on my x86-64 machine:
   9
  10 kernel: DMAR: DMAR:[DMA Write] Request device [05:00.0] fault addr ff5de000
  11         DMAR:[fault reason 05] PTE Write access is not set
  12
  13 Tested-by: Marek Behun <kabel@blackhole.sk>
  14 Signed-off-by: Ben Greear <greearb@candelatech.com>
  15 ---
  16
  17 --- a/drivers/net/wireless/ath/ath10k/wmi.c
  18 +++ b/drivers/net/wireless/ath/ath10k/wmi.c
  19 @@ -4495,7 +4495,7 @@ static int ath10k_wmi_alloc_chunk(struct
  20         if (!num_units)
  21                 return -ENOMEM;
  22
  23 -       paddr = dma_map_single(ar->dev, vaddr, pool_size, DMA_TO_DEVICE);
  24 +       paddr = dma_map_single(ar->dev, vaddr, pool_size, DMA_BIDIRECTIONAL);
  25         if (dma_mapping_error(ar->dev, paddr)) {
  26                 kfree(vaddr);
  27                 return -ENOMEM;