On 02/06/2015 06:20 PM, Geert Uytterhoeven wrote:

On 32-bit platforms using asm-generic/div64.h:

drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c: In function 'gk20a_pllg_calc_rate': drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c:147:79: warning: comparison of distinct pointer types lacks a cast do_div(rate, divider); ^ drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c:147:2: warning: right shift count >= width of type do_div(rate, divider); ^ drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c:147:238: warning: passing argument 1 of '__div64_32' from incompatible pointer type do_div(rate, divider); ^ In file included from arch/parisc/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/include/nvif/os.h:5, from drivers/gpu/drm/nouveau/include/nvkm/core/os.h:3, from drivers/gpu/drm/nouveau/include/nvkm/core/object.h:3, from drivers/gpu/drm/nouveau/include/nvkm/core/subdev.h:3, from drivers/gpu/drm/nouveau/include/nvkm/subdev/clk.h:3, from drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c:25: 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); ^

do_div() is meant for 64-bit by 32-bit division, but both the dividend and divisor are 32-bit here, causing the warning.

As the product of priv->parent_rate and priv->n may no longer fit in u32 soon, change rate from u32 to u64, which also fixes the warning.

Signed-off-by: Geert Uytterhoeven geert@linux-m68k.org

Compile-tested only.

This is v2 of "drm/nouveau/clk: Use plain "/" for 32-bit division".

v2:

• Change rate from u32 to u64 instead of changing the division.

parisc/allmodconfig: http://kisskb.ellerman.id.au/kisskb/buildresult/12358386/

---

drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c index 65c532742b08d1c6..e87a964b8bea4d30 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c @@ -139,7 +139,7 @@ gk20a_pllg_read_mnp(struct gk20a_clk_priv *priv) static u32 gk20a_pllg_calc_rate(struct gk20a_clk_priv *priv) {

• u32 rate;

• u64 rate; u32 divider;

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

Tested-by: Alexandre Courbot acourbot@nvidia.com

Adding Ben as he might want to take this in his tree?