[PATCH 3/3] atomisp: hmm gives a bogus warning on unload

[Alan]

The problem is that we allocated a dummy page to ensure that 0 aka NULL
isn't returned as an ISP pointer into the hmm space. The free routine rather
sensibly checks for bogus NULL frees but is tripped by hmm_cleanup freeing
the dummy.

Split the routine so that we can keep the protection check and avoid the
bogus warning on a cleanup

Signed-off-by: Alan Cox <a...@linux.intel.com>
---
 .../staging/media/atomisp/pci/atomisp2/hmm/hmm.c   |   21 +++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm.c 
b/drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm.c
index a1c81c12718c..dfb9bf54b5d2 100644
--- a/drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm.c
+++ b/drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm.c
@@ -42,6 +42,8 @@ static ia_css_ptr dummy_ptr;
 static bool hmm_initialized;
 struct _hmm_mem_stat hmm_mem_stat;
 
+static void hmm_do_free(ia_css_ptr virt);
+
 /*
  * p: private
  * s: shared
@@ -211,7 +213,7 @@ void hmm_cleanup(void)
        sysfs_remove_group(&atomisp_dev->kobj, atomisp_attribute_group);
 
        /* free dummy memory first */
-       hmm_free(dummy_ptr);
+       hmm_do_free(dummy_ptr);
        dummy_ptr = 0;
 
        hmm_bo_device_exit(&bo_device);
@@ -268,13 +270,10 @@ ia_css_ptr hmm_alloc(size_t bytes, enum hmm_bo_type type,
        return 0;
 }
 
-void hmm_free(ia_css_ptr virt)
+static void hmm_do_free(ia_css_ptr virt)
 {
-       struct hmm_buffer_object *bo;
-
-       WARN_ON(!virt);
-
-       bo = hmm_bo_device_search_start(&bo_device, (unsigned int)virt);
+       struct hmm_buffer_object *bo =
+               hmm_bo_device_search_start(&bo_device, (unsigned int)virt);
 
        if (!bo) {
                dev_err(atomisp_dev,
@@ -290,6 +289,14 @@ void hmm_free(ia_css_ptr virt)
        hmm_bo_unref(bo);
 }
 
+
+void hmm_free(ia_css_ptr virt)
+{
+       WARN_ON(!virt);
+
+       hmm_do_free(virt);
+}
+
 static inline int hmm_check_bo(struct hmm_buffer_object *bo, unsigned int ptr)
 {
        if (!bo) {