From: Of Ard Biesheuvel
> Sent: 14 October 2016 14:41
> PCI devices that are 64-bit DMA capable should set the coherent
> DMA mask as well as the streaming DMA mask. On some architectures,
> these are managed separately, and so the coherent DMA mask will be
> left at its default value of 32 if it is not set explicitly. This
> results in errors such as
>
> r8169 Gigabit Ethernet driver 2.3LK-NAPI loaded
> hwdev DMA mask = 0x00000000ffffffff, dev_addr = 0x00000080fbfff000
> swiotlb: coherent allocation failed for device 0000:02:00.0 size=4096
> CPU: 0 PID: 1062 Comm: systemd-udevd Not tainted 4.8.0+ #35
> Hardware name: AMD Seattle/Seattle, BIOS 10:53:24 Oct 13 2016
>
> on systems without memory that is 32-bit addressable by PCI devices.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
> ---
> v2: dropped the hunk that sets the coherent DMA mask to DMA_BIT_MASK(32),
> which is unnecessary given that it is the default
>
> drivers/net/ethernet/realtek/r8169.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/realtek/r8169.c
> b/drivers/net/ethernet/realtek/r8169.c
> index e55638c7505a..bf000d819a21 100644
> --- a/drivers/net/ethernet/realtek/r8169.c
> +++ b/drivers/net/ethernet/realtek/r8169.c
> @@ -8273,7 +8273,8 @@ static int rtl_init_one(struct pci_dev *pdev, const
> struct pci_device_id *ent)
> if ((sizeof(dma_addr_t) > 4) &&
> (use_dac == 1 || (use_dac == -1 && pci_is_pcie(pdev) &&
> tp->mac_version >= RTL_GIGA_MAC_VER_18)) &&
> - !pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) {
> + !pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) &&
> + !pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64))) {
Isn't there a dma_set_mask_and_coherent() function ?
David
