Re: [PATCH v2 1/1] lib/vsprintf: Add support for printing V4L2 and DRM fourccs

From: Joe Perches
Date: Fri Apr 03 2020 - 13:50:06 EST


On Fri, 2020-04-03 at 19:32 +0200, Mauro Carvalho Chehab wrote:
> Em Fri, 03 Apr 2020 09:56:42 -0700
> Joe Perches <joe@xxxxxxxxxxx> escreveu:
[]
> > How many instances of %p4cc could there be?
>
> That's hard to know... there are several places printing it
> with different ways:
>
> $ git grep -i -E "(dev|pr)_(warn|dbg|info)" drivers/media|grep pixf|wc -l
> 6
> $ git grep -i -E "print" drivers/media|grep pixf|wc -l
> 1
> $ git grep print_fourcc|wc -l
> 7
> $ git grep -i -E "(dev|pr)_(warn|dbg|info)" drivers/media|grep pixelf|wc -l
> 10
> $ git grep -i -E "(dev|pr|v4l)_(warn|dbg|info)" drivers/media|grep format|wc -l
> 60
>
> I bet there are other places besides the above ones, but the thing is, as
> we currently lack a standard way, drivers still have their own ideas
> about how to handle it. Each one does it differently.

My thought was ~100 uses was a minimum, rather like %pI6c.

That's pretty close already, so I suppose that's enough.

It _might_ be useful to use a CONFIG_MEDIA_SUPPORT guard
in lib/vsprintf for this.

cheers, Joe