From: Nick Ewalt <nicholasewalt@google.com>
Date: Mon, 17 Sep 2018 12:39:01 +0000 (-0700)
Subject: staging: gasket: page_table: don't unmap coherent pages
X-Git-Tag: v4.20-rc1~72^2~368
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f8b6a076610f4eb44b0b02c110b7e6f981d7cdc2;p=thirdparty%2Fkernel%2Flinux.git

staging: gasket: page_table: don't unmap coherent pages

Only call dma_unmap_page if there was an associated dma_map_page call.

Signed-off-by: Nick Ewalt <nicholasewalt@google.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/gasket/gasket_page_table.c b/drivers/staging/gasket/gasket_page_table.c
index 8fe27e7d1b53c..33d98043953a5 100644
--- a/drivers/staging/gasket/gasket_page_table.c
+++ b/drivers/staging/gasket/gasket_page_table.c
@@ -610,7 +610,7 @@ static void gasket_perform_unmapping(struct gasket_page_table *pg_tbl,
 
 		/* release the address from the driver, */
 		if (ptes[i].status == PTE_INUSE) {
-			if (ptes[i].dma_addr) {
+			if (ptes[i].page && ptes[i].dma_addr) {
 				dma_unmap_page(pg_tbl->device, ptes[i].dma_addr,
 					       PAGE_SIZE, DMA_BIDIRECTIONAL);
 			}