Re: [Qemu-devel] [RFC 0/2] macio: split out unaligned DMA access into separate functions

[Alexander Graf <agraf@suse.de>]

On 09.03.15 23:24, Mark Cave-Ayland wrote:
> This patchset attempts to separate out the IDE/ATAPI logic from the unaligned
> DMA access logic for macio which provides the following benefits:
> 
> 1) Reduced code complexity
> 
> The existing macio IDE/ATAPI functions were becoming extremely difficult to
> follow through the various callbacks. By splitting up the functions in this
> way it becomes much easier to follow the DMA-specific sections of code.
> 
> 2) Future-proofing
> 
> If/when the block layer becomes able to handle unaligned DMA accesses directly
> then it should be possible to switch out pmac_dma_read() and pmac_dma_write()
> with their unaligned-capable bdrv_*() equivalents without having to change any
> other logic.
> 
> 3) Fix intermittent CDROM detection under -M g3beige
> 
> The code refactoring now correctly handles non-block ATAPI transfers which
> fixes the problem with intermittent CDROM detection with Darwin under
> -M g3beige.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

Works for me, I'd still prefer to just see unaligned bdrv_*() functions
and remove most of the logic we have here.

Either way, I think this is a reasonable intermediate step.


Alex