linux-kernel - [PATCH] drm/mgag200: Fix type of dividend in do

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Message-Id: <1412234986-2001-1-git-send-email-thierry.reding@gmail.com>
Date:	Thu,  2 Oct 2014 09:29:46 +0200
From:	Thierry Reding <thierry.reding@...il.com>
To:	David Airlie <airlied@...ux.ie>
Cc:	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH] drm/mgag200: Fix type of dividend in do_div()

From: Thierry Reding <treding@...dia.com>

The semantics of do_div() are (see include/asm-generic/do_div.h):

	uint32_t do_div(uint64_t *n, uint32_t base)

Using a different type will therefore cause the following warning (as
seen on xtensa/allmodconfig):

	  CC [M]  drivers/gpu/drm/mgag200/mgag200_mode.o
	In file included from arch/xtensa/include/generated/asm/div64.h:1:0,
	                 from include/linux/kernel.h:124,
	                 from include/linux/delay.h:10,
	                 from drivers/gpu/drm/mgag200/mgag200_mode.c:14:
	drivers/gpu/drm/mgag200/mgag200_mode.c: In function 'mga_vga_calculate_mode_bandwidth':
	include/asm-generic/div64.h:43:28: warning: comparison of distinct pointer types lacks a cast
	  (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \
	                            ^
	drivers/gpu/drm/mgag200/mgag200_mode.c:1471:2: note: in expansion of macro 'do_div'
	  do_div(pixels_per_second, total_area);
	  ^
	include/asm-generic/div64.h:43:28: warning: comparison of distinct pointer types lacks a cast
	  (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \
	                            ^
	drivers/gpu/drm/mgag200/mgag200_mode.c:1474:2: note: in expansion of macro 'do_div'
	  do_div(bandwidth, divisor);
	  ^

Signed-off-by: Thierry Reding <treding@...dia.com>
---
 drivers/gpu/drm/mgag200/mgag200_mode.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 83485ab81ce8..4d519dc99db8 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -1455,9 +1455,9 @@ static int mga_vga_get_modes(struct drm_connector *connector)
 static uint32_t mga_vga_calculate_mode_bandwidth(struct drm_display_mode *mode,
 							int bits_per_pixel)
 {
-	uint32_t total_area, divisor;
-	int64_t active_area, pixels_per_second, bandwidth;
 	uint64_t bytes_per_pixel = (bits_per_pixel + 7) / 8;
+	uint32_t total_area, divisor, active_area;
+	uint64_t pixels_per_second, bandwidth;
 
 	divisor = 1024;
 
-- 
2.1.0

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