[PATCH resend] staging: gasket: don't release coherent mappings

[Todd Poynor]

From: Todd Poynor <toddpoynor@xxxxxxxxxx>

coherent address mappings aren't backed by a struct page, don't need to
be released, and don't count as an active page in the page table
bookkeeping.

Signed-off-by: Simon Que <sque@xxxxxxxxxxxx>
Signed-off-by: Todd Poynor <toddpoynor@xxxxxxxxxx>
---
 drivers/staging/gasket/gasket_page_table.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/gasket/gasket_page_table.c b/drivers/staging/gasket/gasket_page_table.c
index dcd52e141f95..e71baa11c8de 100644
--- a/drivers/staging/gasket/gasket_page_table.c
+++ b/drivers/staging/gasket/gasket_page_table.c
@@ -1233,7 +1233,7 @@ static void gasket_perform_unmapping(
 				dma_unmap_page(pg_tbl->device, ptes[i].dma_addr,
 					       PAGE_SIZE, DMA_FROM_DEVICE);
 			}
-			if (gasket_release_page(ptes[i].page))
+			if (ptes[i].page && gasket_release_page(ptes[i].page))
 				--pg_tbl->num_active_pages;
 		}
 		ptes[i].status = PTE_FREE;
-- 
2.18.0.203.gfac676dfb9-goog

Resending, extracted from the previous stack of patches that needs
other cleanups.