drm/i915: forcewake struct mutex locking fixes

Found by the new strict checking for the mutex being held whilst
manipulating the forcewake status.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 3b1147d..9069f28 100644 (file)
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -853,6 +853,7 @@ static int i915_cur_delayinfo(struct seq_file *m, void *unused)
        struct drm_info_node *node = (struct drm_info_node *) m->private;
        struct drm_device *dev = node->minor->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;
+       int ret;
 
        if (IS_GEN5(dev)) {
                u16 rgvswctl = I915_READ16(MEMSWCTL);
@@ -874,6 +875,10 @@ static int i915_cur_delayinfo(struct seq_file *m, void *unused)
                int max_freq;
 
                /* RPSTAT1 is in the GT power well */
+               ret = mutex_lock_interruptible(&dev->struct_mutex);
+               if (ret)
+                       return ret;
+
                gen6_gt_force_wake_get(dev_priv);
 
                rpstat = I915_READ(GEN6_RPSTAT1);
@@ -884,6 +889,9 @@ static int i915_cur_delayinfo(struct seq_file *m, void *unused)
                rpcurdown = I915_READ(GEN6_RP_CUR_DOWN);
                rpprevdown = I915_READ(GEN6_RP_PREV_DOWN);
 
+               gen6_gt_force_wake_put(dev_priv);
+               mutex_unlock(&dev->struct_mutex);
+
                seq_printf(m, "GT_PERF_STATUS: 0x%08x\n", gt_perf_status);
                seq_printf(m, "RPSTAT1: 0x%08x\n", rpstat);
                seq_printf(m, "Render p-state ratio: %d\n",
@@ -918,8 +926,6 @@ static int i915_cur_delayinfo(struct seq_file *m, void *unused)
                max_freq = rp_state_cap & 0xff;
                seq_printf(m, "Max non-overclocked (RP0) frequency: %dMHz\n",
                           max_freq * 50);
-
-               gen6_gt_force_wake_put(dev_priv);
        } else {
                seq_printf(m, "no P-state info available\n");
        }

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 220c3e0..5504ff2 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2585,7 +2585,11 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc)
                ironlake_pch_enable(crtc);
 
        intel_crtc_load_lut(crtc);
+
+       mutex_lock(&dev->struct_mutex);
        intel_update_fbc(dev);
+       mutex_unlock(&dev->struct_mutex);
+
        intel_crtc_update_cursor(crtc, true);
 }
 
@@ -2681,8 +2685,11 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
 
        intel_crtc->active = false;
        intel_update_watermarks(dev);
+
+       mutex_lock(&dev->struct_mutex);
        intel_update_fbc(dev);
        intel_clear_scanline_wait(dev);
+       mutex_unlock(&dev->struct_mutex);
 }
 
 static void ironlake_crtc_dpms(struct drm_crtc *crtc, int mode)
@@ -6973,6 +6980,7 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
         * userspace...
         */
        I915_WRITE(GEN6_RC_STATE, 0);
+       mutex_lock(&dev_priv->dev->struct_mutex);
        gen6_gt_force_wake_get(dev_priv);
 
        /* disable the counters and set deterministic thresholds */
@@ -7075,6 +7083,7 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
        I915_WRITE(GEN6_PMINTRMSK, 0);
 
        gen6_gt_force_wake_put(dev_priv);
+       mutex_unlock(&dev_priv->dev->struct_mutex);
 }
 
 void intel_enable_clock_gating(struct drm_device *dev)