Merge pull request #9549 from hauke/io-tool-sync

io: Open /dev/mem with O_SYNC for uncached access

utils/io/Makefile

@@ -6,7 +6,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=io
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 include $(INCLUDE_DIR)/package.mk
 

utils/io/src/io.c

@@ -343,7 +343,7 @@ main (int argc, char **argv)
 		printf("Attempting to map 0x%lx bytes at address 0x%08lx\n",
 			real_len, real_addr);
 
-	mfd = open("/dev/mem", (memfunc == MEM_READ) ? O_RDONLY : O_RDWR);
+	mfd = open("/dev/mem", (memfunc == MEM_READ) ? (O_RDONLY | O_SYNC) : (O_RDWR | O_SYNC));
 	if (mfd == -1) {
 		perror("open /dev/mem");
 		fprintf(stderr, "Is CONFIG_DEVMEM activated?\n");