Re: [Qemu-devel] [PATCH] Use DMADirection type for dma_bdrv_io

[David Gibson]

On Tue, Feb 21, 2012 at 10:09:01AM +0100, Kevin Wolf wrote:
> Am 21.02.2012 09:35, schrieb Paolo Bonzini:
> > On 02/20/2012 11:50 AM, Alexander Graf wrote:
> >>>>     DMAAIOCB *dbs = qemu_aio_get(&dma_aio_pool, bs, cb, opaque);
> >>>>
> >>>> -    trace_dma_bdrv_io(dbs, bs, sector_num, to_dev);
> >>>> +    trace_dma_bdrv_io(dbs, bs, sector_num, dir);
> >> Was the trace wrong before or is it now? I don't see its definition 
> >> changed anywhere.
> > 
> > Not sure what you mean. :)
> 
> trace-events:
> 
> dma_bdrv_io(void *dbs, void *bs, int64_t sector_num, bool to_dev)
> "dbs=%p bs=%p sector_num=%" PRId64 " to_dev=%d"

Ah, damnit.  Didn't find that file.  I'll resubmit with trace-events
updated too.

> to_dev is declared bool here, and it should also be renamed to dir (the
> unfortunate thing about DMADirection is that it swaps 0 and 1 compared
> to bool to_dev... We need to check carefully that all occurrences have
> been caught.)

Yeah.  And even more unfortunate that afaict there's no way to make
gcc warn on enum<->bool conversions.  Still there are only about 4
callers of dma_bdrv_io() - nearly everything uses the
dma_bdrv_{read,write}() wrappers - so I'm confident I got them all.

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson