Re: [PATCH] libata: implement and use DMA mask configuration helper

[Tejun Heo <htejun@gmail.com>]

Jeff Garzik wrote:
> Tejun Heo wrote:
>> Implement and use DMA mask configuration helper.
>>
>> Signed-off-by: Tejun Heo <htejun@gmail.com>
>> ---
>> This function probably belongs to pci layer.  Put it in libata with
>> pci_test_bits() for the time being.
> 
> AFAIK the default DMA mask is always 32-bit.  Code (often written by me)
> that sets it to a 32-bit mask was just paranoia, and not really needed.
> 
> Hence, the pci_go_64() function I added, found in #upstream.

It isn't in #upstream yet.  Also, at the second thought, there is a
problem with pci_go_64().  DMA masks are not reset after driver is
detached.  Even if the device starts with 32bit DMA masks, after a 64bit
enabled driver is attached and detached, the device's DMA masks are
64bit.  I'm refreshing new-init-model patchset and keeping
pci_configure_dma_masks() for now.

Thanks.

-- 
tejun