From: Paulo Zanoni <paulo.r.zanoni at intel.com> Otherwise, if the BIOS did anything wrong, our first I915_{WRITE,READ} will give us "unclaimed register" messages. V2: Even earlier. V3: Move it to intel_early_sanitize_regs. Bugzilla: http://bugs.freedesktop.org/show_bug.cgi?id=58897 Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com> --- drivers/gpu/drm/i915/i915_dma.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 4fa6beb..e16099b 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -1453,6 +1453,22 @@ static void i915_dump_device_info(struct drm_i915_private *dev_priv) } /** + * intel_early_sanitize_regs - clean up BIOS state + * @dev: DRM device + * + * This function must be called before we do any I915_READ or I915_WRITE. Its + * purpose is to clean up any state left by the BIOS that may affect us when + * reading and/or writing registers. + */ +static void intel_early_sanitize_regs(struct drm_device *dev) +{ + struct drm_i915_private *dev_priv = dev->dev_private; + + if (IS_HASWELL(dev)) + I915_WRITE_NOTRACE(FPGA_DBG, FPGA_DBG_RM_NOCLAIM); +} + +/** * i915_driver_load - setup chip and create an initial config * @dev: DRM device * @flags: startup flags @@ -1542,6 +1558,8 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags) goto put_gmch; } + intel_early_sanitize_regs(dev); + aperture_size = dev_priv->gtt.mappable_end; dev_priv->gtt.mappable = -- 1.7.10.4