drm/i915: Don't disable the GPU for older gen on wedging

If we issue a device level GPU reset on the older gen, it will disable
key components of the GMCH and the display engine. The purpose of
wedging is to simply prevent further GEM usage without disabling KMS, so
we need to be careful when we do issue the reset on wedging.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180726085033.4044-3-chris@chris-wilson.co.uk
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 3ca6a336408522db0de7a4638698ccd98a2daa90..460f256114f7d0fb4f77f8271bc6f48f41261520 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3329,7 +3329,8 @@ void i915_gem_set_wedged(struct drm_i915_private *i915)
        i915->caps.scheduler = 0;
 
        /* Even if the GPU reset fails, it should still stop the engines */
-       intel_gpu_reset(i915, ALL_ENGINES);
+       if (INTEL_GEN(i915) >= 5)
+               intel_gpu_reset(i915, ALL_ENGINES);
 
        /*
         * Make sure no one is running the old callback before we proceed with