From 98787c057fdefdce6230ff46f2c1105835005a4c Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 6 Mar 2009 23:27:52 +0000 Subject: [PATCH] drm/i915: Check for dev->primary->master before dereference. I've hit the occasional oops inside i915_wait_ring() with an indication of a NULL derefence of dev->primary->master. Adding a NULL check is consistent with the other potential users of dev->primary->master. Signed-off-by: Chris Wilson Signed-off-by: Eric Anholt --- drivers/gpu/drm/i915/i915_dma.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index ae83fe0ab374..a818b377e1f7 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -41,7 +41,6 @@ int i915_wait_ring(struct drm_device * dev, int n, const char *caller) { drm_i915_private_t *dev_priv = dev->dev_private; - struct drm_i915_master_private *master_priv = dev->primary->master->driver_priv; drm_i915_ring_buffer_t *ring = &(dev_priv->ring); u32 acthd_reg = IS_I965G(dev) ? ACTHD_I965 : ACTHD; u32 last_acthd = I915_READ(acthd_reg); @@ -58,8 +57,12 @@ int i915_wait_ring(struct drm_device * dev, int n, const char *caller) if (ring->space >= n) return 0; - if (master_priv->sarea_priv) - master_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT; + if (dev->primary->master) { + struct drm_i915_master_private *master_priv = dev->primary->master->driver_priv; + if (master_priv->sarea_priv) + master_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT; + } + if (ring->head != last_head) i = 0; -- 2.20.1