diff --git a/drivers/staging/media/atomisp/pci/hmm/hmm.c b/drivers/staging/media/atomisp/pci/hmm/hmm.c
index 6a5ee46070898b3b15cd44b1cf4ea594a5e3f307..c1cda16f2dc018d10ca9014511dca2c3688ec80b 100644
--- a/drivers/staging/media/atomisp/pci/hmm/hmm.c
+++ b/drivers/staging/media/atomisp/pci/hmm/hmm.c
@@ -39,7 +39,7 @@
 struct hmm_bo_device bo_device;
 struct hmm_pool	dynamic_pool;
 struct hmm_pool	reserved_pool;
-static ia_css_ptr dummy_ptr;
+static ia_css_ptr dummy_ptr = mmgr_EXCEPTION;
 static bool hmm_initialized;
 struct _hmm_mem_stat hmm_mem_stat;
 
@@ -209,7 +209,7 @@ int hmm_init(void)
 
 void hmm_cleanup(void)
 {
-	if (!dummy_ptr)
+	if (dummy_ptr == mmgr_EXCEPTION)
 		return;
 	sysfs_remove_group(&atomisp_dev->kobj, atomisp_attribute_group);
 
@@ -288,7 +288,8 @@ void hmm_free(ia_css_ptr virt)
 
 	dev_dbg(atomisp_dev, "%s: free 0x%08x\n", __func__, virt);
 
-	WARN_ON(!virt);
+	if (WARN_ON(virt == mmgr_EXCEPTION))
+		return;
 
 	bo = hmm_bo_device_search_start(&bo_device, (unsigned int)virt);