[RFC PATCH 094/162] drm/i915/dg1: Do not check r->sgt.pfn for NULL

[Matthew Auld]

From: Kui Wen <kui.wen at intel.com>

When user space does mmap, kernel would map the physical page of local memory
to virtual memory address. The r->sgt.pfn is page address allocated from
local memory and the local memory region is from 0 to LMEM size. Hence the
r->sgt.pfn is possible to be 0, but this's normal case.

Signed-off-by: Kui Wen <kui.wen at intel.com>
---
 drivers/gpu/drm/i915/i915_mm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_mm.c b/drivers/gpu/drm/i915/i915_mm.c
index 43039dc8c607..dcf6b3e5bfdf 100644
--- a/drivers/gpu/drm/i915/i915_mm.c
+++ b/drivers/gpu/drm/i915/i915_mm.c
@@ -62,7 +62,7 @@ static int remap_sg(pte_t *pte, unsigned long addr, void *data)
 {
 	struct remap_pfn *r = data;
 
-	if (GEM_WARN_ON(!r->sgt.pfn))
+	if (GEM_WARN_ON(!use_dma(r->iobase) && !r->sgt.pfn))
 		return -EINVAL;
 
 	/* Special PTE are not associated with any struct page */
-- 
2.26.2