[PATCH] drm/i915: disable FBC when more than one pipe is active

Stefan Bader stefan.bader at canonical.com
Wed Oct 13 07:56:58 UTC 2010


On 10/13/2010 04:35 AM, Ben Hutchings wrote:
> From: Jesse Barnes <jbarnes at virtuousgeek.org>
> 
> commit 9c928d168d4030a230a7a5ee1764721d173f1153 upstream.
> 
> We're really supposed to do this to avoid trouble with underflows when
> multiple planes are active.
> 
> Fixes https://bugs.freedesktop.org/show_bug.cgi?id=26987.
> 
> Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
> Tested-by: fangxun <xunx.fang at intel.com>
> Signed-off-by: Eric Anholt <eric at anholt.net>
> [bwh: Backport to DRM 2.6.33 - drop debugfs integration.]
> Signed-off-by: Ben Hutchings <ben at decadent.org.uk>

Looks simple enough, the remaining DRM_DEBUG_KMS looks a bit odd in the patch
but cannot do any harm.

ACK
> ---
>  drivers/gpu/drm/i915/intel_display.c |   14 ++++++++++++++
>  1 files changed, 14 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 26e7d22..1a671b7 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -1160,8 +1160,12 @@ static void intel_update_fbc(struct drm_crtc *crtc,
>  	struct drm_framebuffer *fb = crtc->fb;
>  	struct intel_framebuffer *intel_fb;
>  	struct drm_i915_gem_object *obj_priv;
> +	struct drm_crtc *tmp_crtc;
>  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
>  	int plane = intel_crtc->plane;
> +	int crtcs_enabled = 0;
> +
> +	DRM_DEBUG_KMS("\n");
>  
>  	if (!i915_powersave)
>  		return;
> @@ -1181,10 +1185,20 @@ static void intel_update_fbc(struct drm_crtc *crtc,
>  	 * If FBC is already on, we just have to verify that we can
>  	 * keep it that way...
>  	 * Need to disable if:
> +	 *   - more than one pipe is active
>  	 *   - changing FBC params (stride, fence, mode)
>  	 *   - new fb is too large to fit in compressed buffer
>  	 *   - going to an unsupported config (interlace, pixel multiply, etc.)
>  	 */
> +	list_for_each_entry(tmp_crtc, &dev->mode_config.crtc_list, head) {
> +		if (tmp_crtc->enabled)
> +			crtcs_enabled++;
> +	}
> +	DRM_DEBUG_KMS("%d pipes active\n", crtcs_enabled);
> +	if (crtcs_enabled > 1) {
> +		DRM_DEBUG_KMS("more than one pipe active, disabling compression\n");
> +		goto out_disable;
> +	}
>  	if (intel_fb->obj->size > dev_priv->cfb_size) {
>  		DRM_DEBUG_KMS("framebuffer too large, disabling "
>  				"compression\n");





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