diff --git a/[refs] b/[refs]
index ca03abb5c558..79c81c9eb866 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a345b23b79f1900e7d87c3165182504419180de4
+refs/heads/master: b26e81b871bd18184968f0bb3f12945906eadfce
diff --git a/trunk/arch/x86/include/asm/amd_iommu_types.h b/trunk/arch/x86/include/asm/amd_iommu_types.h
index c54bc979dc17..e676746a4a30 100644
--- a/trunk/arch/x86/include/asm/amd_iommu_types.h
+++ b/trunk/arch/x86/include/asm/amd_iommu_types.h
@@ -337,6 +337,9 @@ struct amd_iommu {
 	/* if one, we need to send a completion wait command */
 	bool need_sync;
 
+	/* becomes true if a command buffer reset is running */
+	bool reset_in_progress;
+
 	/* default dma_ops domain for that IOMMU */
 	struct dma_ops_domain *default_dom;
 };
diff --git a/trunk/arch/x86/kernel/amd_iommu.c b/trunk/arch/x86/kernel/amd_iommu.c
index 2333d615f5ee..b62a2f64dfc5 100644
--- a/trunk/arch/x86/kernel/amd_iommu.c
+++ b/trunk/arch/x86/kernel/amd_iommu.c
@@ -553,9 +553,16 @@ static void reset_iommu_command_buffer(struct amd_iommu *iommu)
 {
 	pr_err("AMD-Vi: Resetting IOMMU command buffer\n");
 
+	if (iommu->reset_in_progress)
+		panic("AMD-Vi: ILLEGAL_COMMAND_ERROR while resetting command buffer\n");
+
+	iommu->reset_in_progress = true;
+
 	amd_iommu_reset_cmd_buffer(iommu);
 	flush_all_devices_for_iommu(iommu);
 	flush_all_domains_on_iommu(iommu);
+
+	iommu->reset_in_progress = false;
 }
 
 /****************************************************************************