[Intel-gfx] [PATCH 8/9] drm/i915: treat no fb -> fb as simple flip instead of full mode set

[Jesse Barnes]

If for example the BIOS fb is too small for the dual pipe config we detect, we may have valid timings and such, but no fb. The pfit case also hits this path (though currently only fastboots if you hack your mode clock to match). 

--
Jesse Barnes, Intel Open Source Technology Center

-------- Original message --------
From: Daniel Vetter <daniel at ffwll.ch> 
Date: 03/26/2013  5:03 PM  (GMT-08:00) 
To: Jesse Barnes <jbarnes at virtuousgeek.org> 
Cc: intel-gfx at lists.freedesktop.org 
Subject: Re: [Intel-gfx] [PATCH 8/9] drm/i915: treat no fb -> fb as simple
  flip instead of full mode set 
 
On Tue, Mar 26, 2013 at 04:33:11PM -0700, Jesse Barnes wrote:
> In case we don't get an fb from the BIOS, we may still be able to re-use
> existing state and flip a new buffer.
> 
> Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>

This hack here smells extremely fishy. Where do we come up with no fb, but
a real mode and want to actually fastboot?
-Daniel

> ---
>  drivers/gpu/drm/i915/intel_display.c |    4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 0f3c036..f24da1a 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -8109,10 +8109,8 @@ intel_set_config_compute_mode_changes(struct drm_mode_set *set,
>  /* We should be able to check here if the fb has the same properties
>  * and then just flip_or_move it */
>  if (set->crtc->fb != set->fb) {
> -	 /* If we have no fb then treat it as a full mode set */
>  if (set->crtc->fb == NULL) {
> -	 DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
> -	 config->mode_changed = true;
> +	 config->fb_changed = true;
>  } else if (set->fb == NULL) {
>  config->mode_changed = true;
>  } else if (set->fb->depth != set->crtc->fb->depth) {
> -- 
> 1.7.9.5
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

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