[PATCH 3/6] xf86drmMode: Make atomic request structures visible

[Hyungwon Hwang]

Dear,

On Fri, 21 Aug 2015 09:44:42 +0300
Pekka Paalanen <ppaalanen at gmail.com> wrote:

> On Fri, 21 Aug 2015 15:06:58 +0900
> Hyungwon Hwang <human.hwang at samsung.com> wrote:
> 
> > Hi Emil,
> > 
> > On Thu, 20 Aug 2015 17:23:09 +0100
> > Emil Velikov <emil.l.velikov at gmail.com> wrote:
> > 
> > > On 19 August 2015 at 01:58, Hyungwon Hwang
> > > <human.hwang at samsung.com> wrote:
> > > > This patch makes 'struct _drmModeAtomicReqItem' and 'struct
> > > > _drmModeAtomicReq' visible from outside. This is needed for
> > > > userspace applications to use those structures when calling
> > > > drmModeAtomicCommit().
> 
> Yeah, this sounds like a very bad idea.

Yes. Making it visible was not good. But then I think that new API for
getting the value of a request item in the request which are not
applied to the kernel. Because for preparing the buffer, the userspace
program needs width and height which are in the request.

The program can get the value before making it as a request. In that
case, the program such as modetest, which does not understand what the
object id or propery id means, have to be modified to understand them
for extracting the needed value.

How do you think about it? Is modetest just a special program for
testing, and is this support not needed for another real program?

> 
> 
> Thanks,
> pq
> 
> > > >
> > > Hmmm what is missing in the current API, that one needs direct
> > > access to the structs ? If we expose these to the user we'll be
> > > putting a (ABI) hedgehog down our pants (i.e. it might be ok, but
> > > will likely result in a very painful experience).
> > 
> > I also agree with you. I think I should drop this patch, and find
> > another way for modetest.