commit a459443f03224e55385cc59f9efb77da6242eee8
Author: Michel Dänzer <michel.daenzer@amd.com>
Date:   Wed Aug 6 11:08:00 2014 +0900

    PRIME: Don't advertise offload capabilities when acceleration is disabled
    
    Xorg tends to crash if the user tries to actually use the offload
    capabilities with acceleration disabled.

diff --git a/src/radeon_kms.c b/src/radeon_kms.c
index 00d1ce5..ebdbe0c 100644
--- a/src/radeon_kms.c
+++ b/src/radeon_kms.c
@@ -791,10 +791,16 @@ static void RADEONSetupCapabilities(ScrnInfoPtr pScrn)
     pScrn->capabilities = 0;
     ret = drmGetCap(info->dri2.drm_fd, DRM_CAP_PRIME, &value);
     if (ret == 0) {
-	if (value & DRM_PRIME_CAP_EXPORT)
-	    pScrn->capabilities |= RR_Capability_SourceOutput | RR_Capability_SinkOffload;
-	if (value & DRM_PRIME_CAP_IMPORT)
-	    pScrn->capabilities |= RR_Capability_SourceOffload | RR_Capability_SinkOutput;
+	if (value & DRM_PRIME_CAP_EXPORT) {
+	    pScrn->capabilities |= RR_Capability_SourceOutput;
+	    if (!info->r600_shadow_fb && info->dri2.available)
+		pScrn->capabilities |= RR_Capability_SinkOffload;
+	}
+	if (value & DRM_PRIME_CAP_IMPORT) {
+	    pScrn->capabilities |= RR_Capability_SinkOutput;
+	    if (!info->r600_shadow_fb && info->dri2.available)
+		pScrn->capabilities |= RR_Capability_SourceOffload;
+	}
     }
 #endif
 }