[PATCH] drm/ttm: Use ttm_bo_default_io_mem_pfn if io_mem_pfn is NULL

[Michal Srb]

The io_mem_pfn field was added in commit ea642c3216cb2a60d1c0e760ae47ee85c9c16447
and is called unconditionally. However, not all drivers were updated to set it.

Use the ttm_bo_default_io_mem_pfn function if a driver did not set its own.

Signed-off-by: Michal Srb <msrb at suse.com>
---
 drivers/gpu/drm/ttm/ttm_bo_vm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index c8ebb757e36b..e25a99bc519d 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -234,7 +234,10 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
 		if (bo->mem.bus.is_iomem) {
 			/* Iomem should not be marked encrypted */
 			cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot);
-			pfn = bdev->driver->io_mem_pfn(bo, page_offset);
+			if (bdev->driver->io_mem_pfn)
+				pfn = bdev->driver->io_mem_pfn(bo, page_offset);
+			else
+				pfn = ttm_bo_default_io_mem_pfn(bo, page_offset);
 		} else {
 			page = ttm->pages[page_offset];
 			if (unlikely(!page && i == 0)) {
-- 
2.13.6