[Intel-gfx] [PATCH 07/18] drm/i915: fix the __intel_fbc_update() comments

[Chris Wilson]

On Tue, Oct 20, 2015 at 11:49:53AM -0200, Paulo Zanoni wrote:
> Don't try to list in comments the cases where we should enable or
> disable FBC: it varies a lot with the hardware generations and the
> code should be the documentation. Also notice that there's already a
> huge gap between the comments and what's in the code.
> 
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_fbc.c | 26 ++------------------------
>  1 file changed, 2 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
> index e856304..5fa4ce4 100644
> --- a/drivers/gpu/drm/i915/intel_fbc.c
> +++ b/drivers/gpu/drm/i915/intel_fbc.c
> @@ -853,20 +853,8 @@ static bool intel_fbc_hw_tracking_covers_screen(struct intel_crtc *crtc)
>   * __intel_fbc_update - enable/disable FBC as needed, unlocked
>   * @dev_priv: i915 device instance
>   *
> - * Set up the framebuffer compression hardware at mode set time.  We
> - * enable it if possible:
> - *   - plane A only (on pre-965)
> - *   - no pixel mulitply/line duplication
> - *   - no alpha buffer discard
> - *   - no dual wide
> - *   - framebuffer <= max_hdisplay in width, max_vdisplay in height
> - *
> - * We can't assume that any compression will take place (worst case),
> - * so the compressed buffer has to be the same size as the uncompressed
> - * one.  It also must reside (along with the line length buffer) in
> - * stolen memory.
> - *
> - * We need to enable/disable FBC on a global basis.
> + * This function completely reevaluates the status of FBC, then enables,
> + * disables or maintains it on the same state.

By the end, this comment is not strictly true ,right? Since you move
some of the status checking into modeset enable paths. Could you refine
the function comment?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre