[PATCH v3 1/3] drm/gem: don't force writecombine mmap'ing

[Rob Clark <robdclark@gmail.com>]

From: Rob Clark <robdclark@chromium.org>

The driver should be in control of this.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
It is possible that this was masking bugs (ie. not setting appropriate
pgprot) in drivers.  I don't have a particularly good idea for tracking
those down (since I don't have the hw for most drivers).  Unless someone
has a better idea, maybe land this and let driver maintainers fix any
potential fallout in their drivers?

This is necessary for the last patch to fix VGEM brokenness on arm.

v3: rebased on drm-tip

 drivers/gpu/drm/drm_gem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index e6c12c6ec728..84689ccae885 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1109,7 +1109,7 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
 
 	vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
 	vma->vm_private_data = obj;
-	vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
+	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
 
 	/* Take a ref for this mapping of the object, so that the fault
-- 
2.21.0