[PATCH 4.4 24/80] media: staging: omap4iss: Include asm/cacheflush.h after generic includes

From: Greg Kroah-Hartman
Date: Mon Sep 03 2018 - 13:01:25 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Guenter Roeck <linux@xxxxxxxxxxxx>

[ Upstream commit 0894da849f145af51bde88a6b84f95b9c9e0bc66 ]

Including asm/cacheflush.h first results in the following build error
when trying to build sparc32:allmodconfig, because 'struct page' has not
been declared, and the function declaration ends up creating a separate
(private) declaration of struct page (as a result of function arguments
being in the scope of the function declaration and definition, not in
global scope).

The C scoping rules do not just affect variable visibility, they also
affect type declaration visibility.

The end result is that when the actual call site is seen in
<linux/highmem.h>, the 'struct page' type in the caller is not the same
'struct page' that the function was declared with, resulting in:

In file included from arch/sparc/include/asm/page.h:10:0,
...
from drivers/staging/media/omap4iss/iss_video.c:15:
include/linux/highmem.h: In function 'clear_user_highpage':
include/linux/highmem.h:137:31: error:
passing argument 1 of 'sparc_flush_page_to_ram' from incompatible
pointer type

Include generic includes files first to fix the problem.

Fixes: fc96d58c10162 ("[media] v4l: omap4iss: Add support for OMAP4 camera interface - Video devices")
Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
[ Added explanation of C scope rules - Linus ]
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/media/omap4iss/iss_video.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/staging/media/omap4iss/iss_video.c
+++ b/drivers/staging/media/omap4iss/iss_video.c
@@ -11,7 +11,6 @@
* (at your option) any later version.
*/

-#include <asm/cacheflush.h>
#include <linux/clk.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
@@ -22,6 +21,8 @@
#include <media/v4l2-dev.h>
#include <media/v4l2-ioctl.h>

+#include <asm/cacheflush.h>
+
#include "iss_video.h"
#include "iss.h"