drm/i915: use gtfifodbg

[deliverable/linux.git] / drivers / gpu / drm / i915 / intel_display.c

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 7fae6917beab9904e73134273887762c2cba683a..db7ccbbb97c537774e0a9f829a3e151484ab81e9 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8241,6 +8241,7 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
        u32 rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
        u32 gt_perf_status = I915_READ(GEN6_GT_PERF_STATUS);
        u32 pcu_mbox, rc6_mask = 0;
+       u32 gtfifodbg;
        int cur_freq, min_freq, max_freq;
        int i;
 
@@ -8252,6 +8253,13 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
         */
        I915_WRITE(GEN6_RC_STATE, 0);
        mutex_lock(&dev_priv->dev->struct_mutex);
+
+       /* Clear the DBG now so we don't confuse earlier errors */
+       if ((gtfifodbg = I915_READ(GTFIFODBG))) {
+               DRM_ERROR("GT fifo had a previous error %x\n", gtfifodbg);
+               I915_WRITE(GTFIFODBG, gtfifodbg);
+       }
+
        gen6_gt_force_wake_get(dev_priv);
 
        /* disable the counters and set deterministic thresholds */