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. Hence use plain "/" instead.
Signed-off-by: Geert Uytterhoeven geert@linux-m68k.org --- Compile-tested only.
parisc/allmodconfig: http://kisskb.ellerman.id.au/kisskb/buildresult/12358386/ --- drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c index 65c532742b08d1c6..022595876ea4dc85 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c @@ -144,9 +144,8 @@ gk20a_pllg_calc_rate(struct gk20a_clk_priv *priv)
rate = priv->parent_rate * priv->n; divider = priv->m * pl_to_div[priv->pl]; - do_div(rate, divider);
- return rate / 2; + return rate / divider / 2; }
static int
Hi Geert,
On 02/05/2015 01:02 AM, 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. Hence use plain "/" instead.
Signed-off-by: Geert Uytterhoeven geert@linux-m68k.org
Compile-tested only.
parisc/allmodconfig: http://kisskb.ellerman.id.au/kisskb/buildresult/12358386/
drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c index 65c532742b08d1c6..022595876ea4dc85 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c @@ -144,9 +144,8 @@ gk20a_pllg_calc_rate(struct gk20a_clk_priv *priv)
rate = priv->parent_rate * priv->n; divider = priv->m * pl_to_div[priv->pl];
do_div(rate, divider);
return rate / 2;
- return rate / divider / 2;
I agree there is a problem here, but considering the theoretical values that rate can take, could we rather fix this by making rate a u64? With the current maximum values of priv->parent_rate and priv->n, rate might approach dangerously to the u32 limit and I believe casting it to u64 would be safer.
Hi Alexandre,
On Fri, Feb 6, 2015 at 7:50 AM, Alexandre Courbot acourbot@nvidia.com wrote:
On 02/05/2015 01:02 AM, 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. Hence use plain "/" instead.
Signed-off-by: Geert Uytterhoeven geert@linux-m68k.org
Compile-tested only.
parisc/allmodconfig: http://kisskb.ellerman.id.au/kisskb/buildresult/12358386/
drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c index 65c532742b08d1c6..022595876ea4dc85 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.c @@ -144,9 +144,8 @@ gk20a_pllg_calc_rate(struct gk20a_clk_priv *priv)
rate = priv->parent_rate * priv->n; divider = priv->m * pl_to_div[priv->pl];
do_div(rate, divider);return rate / 2;
return rate / divider / 2;I agree there is a problem here, but considering the theoretical values that rate can take, could we rather fix this by making rate a u64? With the current maximum values of priv->parent_rate and priv->n, rate might approach dangerously to the u32 limit and I believe casting it to u64 would be safer.
Yes, that's better.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
dri-devel@lists.freedesktop.org
-
Alexandre Courbot -
Geert Uytterhoeven