> On 14 Oct 2016, at 14:42, David Laight<david.lai...@aculab.com> wrote:
>
> 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
>
