From: Thierry Reding <tred...@nvidia.com>

The semantics of do_div() are (see include/asm-generic/div64.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/nouveau/core/subdev/clock/gk20a.o
        In file included from arch/xtensa/include/generated/asm/div64.h:1:0,
                         from include/linux/kernel.h:124,
                         from include/linux/list.h:8,
                         from include/linux/preempt.h:10,
                         from include/linux/spinlock.h:50,
                         from include/linux/mmzone.h:7,
                         from include/linux/gfp.h:5,
                         from include/linux/slab.h:14,
                         from drivers/gpu/drm/nouveau/core/os.h:5,
                         from 
drivers/gpu/drm/nouveau/core/include/core/object.h:4,
                         from 
drivers/gpu/drm/nouveau/core/include/core/device.h:4,
                         from 
drivers/gpu/drm/nouveau/core/include/subdev/clock.h:4,
                         from 
drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c:90:
        drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c: In function 
'gk20a_pllg_calc_rate':
        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/nouveau/core/subdev/clock/gk20a.c:146:2: note: in 
expansion of macro 'do_div'
          do_div(rate, divider);
          ^
        drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c:146:2: warning: right 
shift count >= width of type
        In file included from arch/xtensa/include/generated/asm/div64.h:1:0,
                         from include/linux/kernel.h:124,
                         from include/linux/list.h:8,
                         from include/linux/preempt.h:10,
                         from include/linux/spinlock.h:50,
                         from include/linux/mmzone.h:7,
                         from include/linux/gfp.h:5,
                         from include/linux/slab.h:14,
                         from drivers/gpu/drm/nouveau/core/os.h:5,
                         from 
drivers/gpu/drm/nouveau/core/include/core/object.h:4,
                         from 
drivers/gpu/drm/nouveau/core/include/core/device.h:4,
                         from 
drivers/gpu/drm/nouveau/core/include/subdev/clock.h:4,
                         from 
drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c:90:
        include/asm-generic/div64.h:48:11: warning: passing argument 1 of 
'__div64_32' from incompatible pointer type
           __rem = __div64_32(&(n), __base); \
                   ^
        drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c:146:2: note: in 
expansion of macro 'do_div'
          do_div(rate, divider);
          ^
        include/asm-generic/div64.h:35:17: note: expected 'uint64_t *' but 
argument is of type 'u32 *'
         extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);

Signed-off-by: Thierry Reding <treding at nvidia.com>
---
 drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c 
b/drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c
index 425a8d5e9129..c571437afbd2 100644
--- a/drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c
+++ b/drivers/gpu/drm/nouveau/core/subdev/clock/gk20a.c
@@ -138,7 +138,7 @@ gk20a_pllg_read_mnp(struct gk20a_clock_priv *priv)
 static u32
 gk20a_pllg_calc_rate(struct gk20a_clock_priv *priv)
 {
-       u32 rate;
+       u64 rate;
        u32 divider;

        rate = priv->parent_rate * priv->n;
-- 
2.1.0

Reply via email to