drm/i915: Gen2 FBC1 CFB pitch wants 32B units

On gen2 the compressed frame buffer pitch is specified in 32B units
rather than the 64B units used on gen3+.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 3cd521f3823b..599d445f7ce9 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -104,8 +104,11 @@ static void i8xx_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
         if (fb->pitches[0] < cfb_pitch)
                 cfb_pitch = fb->pitches[0];
 
-        /* FBC_CTL wants 64B units */
-        cfb_pitch = (cfb_pitch / 64) - 1;
+        /* FBC_CTL wants 32B or 64B units */
+        if (IS_GEN2(dev))
+                cfb_pitch = (cfb_pitch / 32) - 1;
+        else
+                cfb_pitch = (cfb_pitch / 64) - 1;
         plane = intel_crtc->plane == 0 ? FBC_CTL_PLANEA : FBC_CTL_PLANEB;
 
         /* Clear old tags */