We need to get hdisplay and vdisplay in a few places so create a
helper to make our job easier.

Note that drm_crtc_check_viewport() and intel_modeset_pipe_config() were
previously making adjustments for doublescan modes and vscan > 1 modes,
which was incorrect.  Using our new helper fixes this mistake.

v2 (by Matt): Use new stereo doubling function (suggested by Ville)

v3 (by Matt):
 - Add missing kerneldoc (Daniel)
 - Use drm_mode_copy() (Jani)

v4 (by Matt):
 - Drop stereo doubling function again; add 'stereo only' flag
   to drm_mode_set_crtcinfo() instead (Ville)

v5 (by Matt):
 - Note behavioral change in drm_crtc_check_viewport() and
   intel_modeset_pipe_config(). (Ander)
 - Describe new adjustment flags in drm_mode_set_crtcinfo()'s
   kerneldoc. (Ander)

Cc: dri-devel@lists.freedesktop.org
Suggested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Reviewed-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For QXL hw we really want the bits to be replaced as we change
the preferred mode on the fly, and the same goes for virgl when
I get to it, however the original fix for this seems to have caused
a wierd regression on Intel G33 that in a stunning display of failure
at opposition to his normal self, Daniel failed to diagnose.

So we are left doing this, ugly ugly ugly ugly, Daniel you fixed
that G33 yet?, ugly, ugly.
Tested-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

It' unused and there's also not really any way to make it work with
the current code. So better rip it out.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

- Tune down yelling RETURNS.
- OCD align all the parameters the same.
- Add missing kerneldoc, which also means that we need to include the
  kerneldoc from the drm_modes.h header now.
- Add missing Returns: sections.
- General polish and clarification - especially the kerneldoc for the
  mode creation helpers seems to have been some good specimen of
  copypasta gone wrong.

All actual code changes have all been extracted into prep patches
since there was simply too much to polish.

v2: More polish for the command line modeline functions.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Totally unused and actually redundant with maxX for display mode
validation. The fb helper otoh needs to check pitch limits,
but that is delegated into drivers instead.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It never fails and no one ever checked anyway.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There's a neat FIXME asking whether this is really need. I'd
say really no.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I want to also include kerneldoc from the header (for static inline
functions and structs), but fishing the right pieces out of a giant
header is a real pain. So split things out.

Note that it's not a really clean header with sane include orders, but
given's drm historical knack for giant headers detangling this is a
major task.

v2: Also extract struct drm_cmdline_mode.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>