[Intel-gfx] [PATCH 02/16] drm/i915: fix the FBC work allocation failure path

[Ville Syrjälä]

On Tue, Sep 01, 2015 at 12:07:01PM +0200, Daniel Vetter wrote:
> On Fri, Aug 28, 2015 at 11:50:08AM -0300, Paulo Zanoni wrote:
> > 2015-08-28 11:20 GMT-03:00 Ville Syrjälä <ville.syrjala at linux.intel.com>:
> > > On Fri, Aug 14, 2015 at 06:34:07PM -0300, Paulo Zanoni wrote:
> > >> Always update the currrent crtc, fb and vertical offset after calling
> > >> enable_fbc. We were forgetting to do so along the failure paths when
> > >> enabling fbc synchronously. Fix this with a new helper to enable_fbc()
> > >> and update the state simultaneously.
> > >>
> > >> v2: Improve commit message (Chris).
> > >>
> > >> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > >> ---
> > >>  drivers/gpu/drm/i915/intel_fbc.c | 27 +++++++++++++++++----------
> > >>  1 file changed, 17 insertions(+), 10 deletions(-)
> > >>
> > >> diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
> > >> index c97aba2..fa9b004 100644
> > >> --- a/drivers/gpu/drm/i915/intel_fbc.c
> > >> +++ b/drivers/gpu/drm/i915/intel_fbc.c
> > >> @@ -308,6 +308,18 @@ bool intel_fbc_enabled(struct drm_i915_private *dev_priv)
> > >>       return dev_priv->fbc.enabled;
> > >>  }
> > >>
> > >> +static void intel_fbc_enable(struct intel_crtc *crtc,
> > >> +                          struct drm_framebuffer *fb)
> > >
> > > fb could be const
> > 
> > I guess a lot of things could be constified, if we decide to do this.
> 
> Personally I like const on .data (especially vfunc tables since those are
> nice to create exploits if they're writable and you can get at them). And
> for core functions/vfuncs where the const has a semantic meaning.
> Otherwise I personally don't see to much value in sprinkling const all
> over.

I especially like making display mode, state, etc. structs const to make
it clear which functions can change them and which can't. IMO
drm_framebuffer could use the same treatment.

-- 
Ville Syrjälä
Intel OTC