Re: [Qemu-devel] [PATCH] hw/dma/xilinx_axidma: debug printf fixups

[Andrew Jones <drjones@redhat.com>]

On Tue, Jan 05, 2016 at 05:45:57PM -0800, Alistair Francis wrote:
> On Tue, Jan 5, 2016 at 7:32 AM, Andrew Jones <drjones@redhat.com> wrote:
> > On Tue, Jan 05, 2016 at 07:07:22AM -0700, Eric Blake wrote:
> >> On 01/05/2016 06:22 AM, Andrew Jones wrote:
> >> > (Found by grepping for broken PRI users.)
> >> >
> >> > Signed-off-by: Andrew Jones <drjones@redhat.com>
> >> > ---
> >> >  hw/dma/xilinx_axidma.c | 8 ++++----
> >> >  1 file changed, 4 insertions(+), 4 deletions(-)
> >> >
> >> > diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
> >> > index b1cfa11356a26..2ab0772cd19ae 100644
> >> > --- a/hw/dma/xilinx_axidma.c
> >> > +++ b/hw/dma/xilinx_axidma.c
> >> > @@ -180,10 +180,10 @@ static inline int streamid_from_addr(hwaddr addr)
> >> >  #ifdef DEBUG_ENET
> >> >  static void stream_desc_show(struct SDesc *d)
> >> >  {
> >> > -    qemu_log("buffer_addr  = " PRIx64 "\n", d->buffer_address);
> >> > -    qemu_log("nxtdesc      = " PRIx64 "\n", d->nxtdesc);
> >> > -    qemu_log("control      = %x\n", d->control);
> >> > -    qemu_log("status       = %x\n", d->status);
> >> > +    qemu_log("buffer_addr  = 0x%" PRIx64 "\n", d->buffer_address);
> >> > +    qemu_log("nxtdesc      = 0x%" PRIx64 "\n", d->nxtdesc);
> >> > +    qemu_log("control      = 0x%x\n", d->control);
> >> > +    qemu_log("status       = 0x%x\n", d->status);
> >>
> >> This is dead code.  Nothing uses stream_desc_show() even when DEBUG_ENET
> >> is defined.  I'd just delete the function and #ifdef altogether, instead.
> >
> > Sounds good, but I guess I'll leave the keep+fix vs. throw decision to the
> > maintainers, rather than to submit a v2 ripping it out.
> 
> I don't see any reason to keep dead code around. I think it should be removed.

The reason I see, is that this function could be useful to temporarily add it
different places while debugging. I.e. this is no different than a collection
of temporary printf's, but saves the time of rewriting those printf's
whenever/wherever they're necessary. I suspect that's why this function is
here in the first place.

That said, I don't debug this file, so I don't really have any say on
whether or not it's of any use now. Anyway, based on the fact this function
has PRI bugs in it that would break compilation, I guess nobody debugs this
file with DEBUG_ENET turned on.

> 
> If you send a V2 removing it (or a new patch altogether) I'll review it.

OK, sending a new patch that kills it.

Thanks,
drew