> -----Original Message-----
> From: Intel-gfx <intel-gfx-boun...@lists.freedesktop.org> On Behalf Of Ville
> Syrjala
> Sent: Wednesday, November 24, 2021 1:37 PM
> To: intel-gfx@lists.freedesktop.org
> Subject: [Intel-gfx] [PATCH 01/20] drm/i915/fbc: Eliminate racy
> intel_fbc_is_active() usage
>
> From: Ville Syrjälä <ville.syrj...@linux.intel.com>
>
> The ilk fbc watermark computation uses intel_fbc_is_active() which is racy
> since
> we don't know whether FBC will be enabled or not at some point. So let's just
> assume it will be if both HAS_FBC() and the modparam agree.
>
> Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
Reviewed-by: Mika Kahola <mika.kah...@intel.com>
> ---
> drivers/gpu/drm/i915/intel_pm.c | 9 ++-------
> 1 file changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 01fa3fac1b57..18fbdd204a93 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3369,13 +3369,8 @@ static void ilk_wm_merge(struct drm_i915_private
> *dev_priv,
> }
>
> /* ILK: LP2+ must be disabled when FBC WM is disabled but FBC enabled
> */
> - /*
> - * FIXME this is racy. FBC might get enabled later.
> - * What we should check here is whether FBC can be
> - * enabled sometime later.
> - */
> - if (DISPLAY_VER(dev_priv) == 5 && !merged->fbc_wm_enabled &&
> - intel_fbc_is_active(&dev_priv->fbc)) {
> + if (DISPLAY_VER(dev_priv) == 5 && HAS_FBC(dev_priv) &&
> + dev_priv->params.enable_fbc && !merged->fbc_wm_enabled) {
> for (level = 2; level <= max_level; level++) {
> struct intel_wm_level *wm = &merged->wm[level];
>
> --
> 2.32.0
