Semaphores cause issues when DMAR is enabled. So if we are set to per-chip default, and we are on SNB, we can enable semaphores as long as SMAR is disabled. Signed-off-by: Eugeni Dodonov <eugeni.dodonov at intel.com> --- drivers/gpu/drm/i915/i915_drv.c | 2 ++ drivers/gpu/drm/i915/i915_gem_execbuffer.c | 4 +++- 2 files changed, 5 insertions(+), 1 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 355f1ab..565725c 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -214,6 +214,7 @@ static const struct intel_device_info intel_sandybridge_d_info = { .need_gfx_hws = 1, .has_hotplug = 1, .has_bsd_ring = 1, .has_blt_ring = 1, + .enable_semaphores = 1, }; static const struct intel_device_info intel_sandybridge_m_info = { @@ -222,6 +223,7 @@ static const struct intel_device_info intel_sandybridge_m_info = { .has_fbc = 1, .has_bsd_ring = 1, .has_blt_ring = 1, + .enable_semaphores = 1, }; static const struct intel_device_info intel_ivybridge_d_info = { diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 094ff4c..0510735 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -32,6 +32,7 @@ #include "i915_drv.h" #include "i915_trace.h" #include "intel_drv.h" +#include <linux/intel-iommu.h> struct change_domains { uint32_t invalidate_domains; @@ -758,7 +759,8 @@ i915_gem_execbuffer_sync_rings(struct drm_i915_gem_object *obj, if (from == NULL || to == from) return 0; - if (i915_semaphores < 0 && ENABLE_SEMAPHORES(obj->base.dev)) + /* Only enable semaphores if DMAR is disabled */ + if (i915_semaphores < 0 && ENABLE_SEMAPHORES(obj->base.dev) && dmar_disabled) enable_semaphores = 1; /* XXX gpu semaphores are implicated in various hard hangs on SNB */ -- 1.7.7.3