* Re: [PATCH] drm/amdgpu: Initialize shadow to false in gfx_v9_0_rlcg_wreg
2020-03-18 0:25 [PATCH] drm/amdgpu: Initialize shadow to false in gfx_v9_0_rlcg_wreg Nathan Chancellor
@ 2020-03-18 20:11 ` Nick Desaulniers
2020-03-18 20:26 ` Joe Perches
2020-03-18 21:04 ` [PATCH v2] drm/amdgpu: Remove unnecessary variable shadow " Nathan Chancellor
2 siblings, 0 replies; 7+ messages in thread
From: Nick Desaulniers @ 2020-03-18 20:11 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Alex Deucher, Christian König, David (ChunMing) Zhou,
amd-gfx list, dri-devel, LKML, clang-built-linux
On Tue, Mar 17, 2020 at 5:25 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> clang warns:
>
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:754:6: warning: variable 'shadow'
> is used uninitialized whenever 'if' condition is
> false [-Wsometimes-uninitialized]
> if (offset == grbm_cntl || offset == grbm_idx)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:757:6: note: uninitialized use
> occurs here
> if (shadow) {
> ^~~~~~
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:754:2: note: remove the 'if' if
> its condition is always true
> if (offset == grbm_cntl || offset == grbm_idx)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:738:13: note: initialize the
> variable 'shadow' to silence this warning
> bool shadow;
> ^
> = 0
> 1 warning generated.
>
> It is not wrong so initialize shadow to false to ensure shadow is always
> used initialized.
Yep, thanks for the patch.
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
>
> Fixes: 2e0cc4d48b91 ("drm/amdgpu: revise RLCG access path")
> Link: https://github.com/ClangBuiltLinux/linux/issues/936
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> index 7bc2486167e7..affbff76758c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> @@ -735,7 +735,7 @@ void gfx_v9_0_rlcg_wreg(struct amdgpu_device *adev, u32 offset, u32 v)
> static void *spare_int;
> static uint32_t grbm_cntl;
> static uint32_t grbm_idx;
> - bool shadow;
> + bool shadow = false;
>
> scratch_reg0 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG0_BASE_IDX] + mmSCRATCH_REG0)*4;
> scratch_reg1 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG1_BASE_IDX] + mmSCRATCH_REG1)*4;
> --
> 2.26.0.rc1
>
> --
> You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20200318002500.52471-1-natechancellor%40gmail.com.
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] drm/amdgpu: Initialize shadow to false in gfx_v9_0_rlcg_wreg
2020-03-18 0:25 [PATCH] drm/amdgpu: Initialize shadow to false in gfx_v9_0_rlcg_wreg Nathan Chancellor
2020-03-18 20:11 ` Nick Desaulniers
@ 2020-03-18 20:26 ` Joe Perches
2020-03-18 20:43 ` Nick Desaulniers
2020-03-18 21:04 ` [PATCH v2] drm/amdgpu: Remove unnecessary variable shadow " Nathan Chancellor
2 siblings, 1 reply; 7+ messages in thread
From: Joe Perches @ 2020-03-18 20:26 UTC (permalink / raw)
To: Nathan Chancellor, Alex Deucher, Christian König,
David (ChunMing) Zhou
Cc: amd-gfx, dri-devel, linux-kernel, clang-built-linux
On Tue, 2020-03-17 at 17:25 -0700, Nathan Chancellor wrote:
> clang warns:
>
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:754:6: warning: variable 'shadow'
> is used uninitialized whenever 'if' condition is
> false [-Wsometimes-uninitialized]
> if (offset == grbm_cntl || offset == grbm_idx)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:757:6: note: uninitialized use
> occurs here
> if (shadow) {
> ^~~~~~
Wouldn't it be better to get rid of the shadow variable completely?
---
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index 7bc248..496b9e 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -735,7 +735,6 @@ void gfx_v9_0_rlcg_wreg(struct amdgpu_device *adev, u32 offset, u32 v)
static void *spare_int;
static uint32_t grbm_cntl;
static uint32_t grbm_idx;
- bool shadow;
scratch_reg0 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG0_BASE_IDX] + mmSCRATCH_REG0)*4;
scratch_reg1 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG1_BASE_IDX] + mmSCRATCH_REG1)*4;
@@ -751,10 +750,7 @@ void gfx_v9_0_rlcg_wreg(struct amdgpu_device *adev, u32 offset, u32 v)
return;
}
- if (offset == grbm_cntl || offset == grbm_idx)
- shadow = true;
-
- if (shadow) {
+ if (offset == grbm_cntl || offset == grbm_idx) {
if (offset == grbm_cntl)
writel(v, scratch_reg2);
else if (offset == grbm_idx)
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] drm/amdgpu: Initialize shadow to false in gfx_v9_0_rlcg_wreg
2020-03-18 20:26 ` Joe Perches
@ 2020-03-18 20:43 ` Nick Desaulniers
0 siblings, 0 replies; 7+ messages in thread
From: Nick Desaulniers @ 2020-03-18 20:43 UTC (permalink / raw)
To: Joe Perches
Cc: Nathan Chancellor, Alex Deucher, Christian König,
David (ChunMing) Zhou, amd-gfx list, dri-devel, LKML,
clang-built-linux
On Wed, Mar 18, 2020 at 1:28 PM Joe Perches <joe@perches.com> wrote:
>
> On Tue, 2020-03-17 at 17:25 -0700, Nathan Chancellor wrote:
> > clang warns:
> >
> > drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:754:6: warning: variable 'shadow'
> > is used uninitialized whenever 'if' condition is
> > false [-Wsometimes-uninitialized]
> > if (offset == grbm_cntl || offset == grbm_idx)
> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:757:6: note: uninitialized use
> > occurs here
> > if (shadow) {
> > ^~~~~~
>
> Wouldn't it be better to get rid of the shadow variable completely?
Yes, much better indeed. Seems it only has one use.
> ---
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> index 7bc248..496b9e 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> @@ -735,7 +735,6 @@ void gfx_v9_0_rlcg_wreg(struct amdgpu_device *adev, u32 offset, u32 v)
> static void *spare_int;
> static uint32_t grbm_cntl;
> static uint32_t grbm_idx;
> - bool shadow;
>
> scratch_reg0 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG0_BASE_IDX] + mmSCRATCH_REG0)*4;
> scratch_reg1 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG1_BASE_IDX] + mmSCRATCH_REG1)*4;
> @@ -751,10 +750,7 @@ void gfx_v9_0_rlcg_wreg(struct amdgpu_device *adev, u32 offset, u32 v)
> return;
> }
>
> - if (offset == grbm_cntl || offset == grbm_idx)
> - shadow = true;
> -
> - if (shadow) {
> + if (offset == grbm_cntl || offset == grbm_idx) {
> if (offset == grbm_cntl)
> writel(v, scratch_reg2);
> else if (offset == grbm_idx)
>
>
> --
> You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/3a997f4ee640e607a171a19668f5f5484062116c.camel%40perches.com.
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2] drm/amdgpu: Remove unnecessary variable shadow in gfx_v9_0_rlcg_wreg
2020-03-18 0:25 [PATCH] drm/amdgpu: Initialize shadow to false in gfx_v9_0_rlcg_wreg Nathan Chancellor
2020-03-18 20:11 ` Nick Desaulniers
2020-03-18 20:26 ` Joe Perches
@ 2020-03-18 21:04 ` Nathan Chancellor
2020-03-18 21:07 ` Nick Desaulniers
2 siblings, 1 reply; 7+ messages in thread
From: Nathan Chancellor @ 2020-03-18 21:04 UTC (permalink / raw)
To: Alex Deucher, David (ChunMing) Zhou, Christian König
Cc: amd-gfx, dri-devel, linux-kernel, clang-built-linux,
Nathan Chancellor, Joe Perches, Nick Desaulniers
clang warns:
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:754:6: warning: variable 'shadow'
is used uninitialized whenever 'if' condition is
false [-Wsometimes-uninitialized]
if (offset == grbm_cntl || offset == grbm_idx)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:757:6: note: uninitialized use
occurs here
if (shadow) {
^~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:754:2: note: remove the 'if' if
its condition is always true
if (offset == grbm_cntl || offset == grbm_idx)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:738:13: note: initialize the
variable 'shadow' to silence this warning
bool shadow;
^
= 0
1 warning generated.
shadow is only assigned in one condition and used as the condition for
another if statement; combine the two if statements and remove shadow
to make the code cleaner and resolve this warning.
Fixes: 2e0cc4d48b91 ("drm/amdgpu: revise RLCG access path")
Link: https://github.com/ClangBuiltLinux/linux/issues/936
Suggested-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
v1 -> v2:
* Remove shadow altogether, as suggested by Joe Perches.
* Add Nick's Reviewed-by, as I assume it still stands.
drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index 7bc2486167e7..496b9edca3c3 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -735,7 +735,6 @@ void gfx_v9_0_rlcg_wreg(struct amdgpu_device *adev, u32 offset, u32 v)
static void *spare_int;
static uint32_t grbm_cntl;
static uint32_t grbm_idx;
- bool shadow;
scratch_reg0 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG0_BASE_IDX] + mmSCRATCH_REG0)*4;
scratch_reg1 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG1_BASE_IDX] + mmSCRATCH_REG1)*4;
@@ -751,10 +750,7 @@ void gfx_v9_0_rlcg_wreg(struct amdgpu_device *adev, u32 offset, u32 v)
return;
}
- if (offset == grbm_cntl || offset == grbm_idx)
- shadow = true;
-
- if (shadow) {
+ if (offset == grbm_cntl || offset == grbm_idx) {
if (offset == grbm_cntl)
writel(v, scratch_reg2);
else if (offset == grbm_idx)
--
2.26.0.rc1
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v2] drm/amdgpu: Remove unnecessary variable shadow in gfx_v9_0_rlcg_wreg
2020-03-18 21:04 ` [PATCH v2] drm/amdgpu: Remove unnecessary variable shadow " Nathan Chancellor
@ 2020-03-18 21:07 ` Nick Desaulniers
2020-03-19 3:15 ` Alex Deucher
0 siblings, 1 reply; 7+ messages in thread
From: Nick Desaulniers @ 2020-03-18 21:07 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Alex Deucher, David (ChunMing) Zhou, Christian König,
amd-gfx list, dri-devel, LKML, clang-built-linux, Joe Perches
On Wed, Mar 18, 2020 at 2:05 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> clang warns:
>
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:754:6: warning: variable 'shadow'
> is used uninitialized whenever 'if' condition is
> false [-Wsometimes-uninitialized]
> if (offset == grbm_cntl || offset == grbm_idx)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:757:6: note: uninitialized use
> occurs here
> if (shadow) {
> ^~~~~~
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:754:2: note: remove the 'if' if
> its condition is always true
> if (offset == grbm_cntl || offset == grbm_idx)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:738:13: note: initialize the
> variable 'shadow' to silence this warning
> bool shadow;
> ^
> = 0
> 1 warning generated.
>
> shadow is only assigned in one condition and used as the condition for
> another if statement; combine the two if statements and remove shadow
> to make the code cleaner and resolve this warning.
>
> Fixes: 2e0cc4d48b91 ("drm/amdgpu: revise RLCG access path")
> Link: https://github.com/ClangBuiltLinux/linux/issues/936
> Suggested-by: Joe Perches <joe@perches.com>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
>
> v1 -> v2:
>
> * Remove shadow altogether, as suggested by Joe Perches.
> * Add Nick's Reviewed-by, as I assume it still stands.
yep, thanks
>
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> index 7bc2486167e7..496b9edca3c3 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> @@ -735,7 +735,6 @@ void gfx_v9_0_rlcg_wreg(struct amdgpu_device *adev, u32 offset, u32 v)
> static void *spare_int;
> static uint32_t grbm_cntl;
> static uint32_t grbm_idx;
> - bool shadow;
>
> scratch_reg0 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG0_BASE_IDX] + mmSCRATCH_REG0)*4;
> scratch_reg1 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG1_BASE_IDX] + mmSCRATCH_REG1)*4;
> @@ -751,10 +750,7 @@ void gfx_v9_0_rlcg_wreg(struct amdgpu_device *adev, u32 offset, u32 v)
> return;
> }
>
> - if (offset == grbm_cntl || offset == grbm_idx)
> - shadow = true;
> -
> - if (shadow) {
> + if (offset == grbm_cntl || offset == grbm_idx) {
> if (offset == grbm_cntl)
> writel(v, scratch_reg2);
> else if (offset == grbm_idx)
> --
> 2.26.0.rc1
>
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v2] drm/amdgpu: Remove unnecessary variable shadow in gfx_v9_0_rlcg_wreg
2020-03-18 21:07 ` Nick Desaulniers
@ 2020-03-19 3:15 ` Alex Deucher
0 siblings, 0 replies; 7+ messages in thread
From: Alex Deucher @ 2020-03-19 3:15 UTC (permalink / raw)
To: Nick Desaulniers
Cc: Nathan Chancellor, David (ChunMing) Zhou, LKML, dri-devel,
clang-built-linux, amd-gfx list, Alex Deucher, Joe Perches,
Christian König
On Wed, Mar 18, 2020 at 5:08 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> On Wed, Mar 18, 2020 at 2:05 PM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > clang warns:
> >
> > drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:754:6: warning: variable 'shadow'
> > is used uninitialized whenever 'if' condition is
> > false [-Wsometimes-uninitialized]
> > if (offset == grbm_cntl || offset == grbm_idx)
> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:757:6: note: uninitialized use
> > occurs here
> > if (shadow) {
> > ^~~~~~
> > drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:754:2: note: remove the 'if' if
> > its condition is always true
> > if (offset == grbm_cntl || offset == grbm_idx)
> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c:738:13: note: initialize the
> > variable 'shadow' to silence this warning
> > bool shadow;
> > ^
> > = 0
> > 1 warning generated.
> >
> > shadow is only assigned in one condition and used as the condition for
> > another if statement; combine the two if statements and remove shadow
> > to make the code cleaner and resolve this warning.
> >
> > Fixes: 2e0cc4d48b91 ("drm/amdgpu: revise RLCG access path")
> > Link: https://github.com/ClangBuiltLinux/linux/issues/936
> > Suggested-by: Joe Perches <joe@perches.com>
> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Applied. thanks!
Alex
> > ---
> >
> > v1 -> v2:
> >
> > * Remove shadow altogether, as suggested by Joe Perches.
> > * Add Nick's Reviewed-by, as I assume it still stands.
>
> yep, thanks
>
> >
> > drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 6 +-----
> > 1 file changed, 1 insertion(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> > index 7bc2486167e7..496b9edca3c3 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> > @@ -735,7 +735,6 @@ void gfx_v9_0_rlcg_wreg(struct amdgpu_device *adev, u32 offset, u32 v)
> > static void *spare_int;
> > static uint32_t grbm_cntl;
> > static uint32_t grbm_idx;
> > - bool shadow;
> >
> > scratch_reg0 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG0_BASE_IDX] + mmSCRATCH_REG0)*4;
> > scratch_reg1 = adev->rmmio + (adev->reg_offset[GC_HWIP][0][mmSCRATCH_REG1_BASE_IDX] + mmSCRATCH_REG1)*4;
> > @@ -751,10 +750,7 @@ void gfx_v9_0_rlcg_wreg(struct amdgpu_device *adev, u32 offset, u32 v)
> > return;
> > }
> >
> > - if (offset == grbm_cntl || offset == grbm_idx)
> > - shadow = true;
> > -
> > - if (shadow) {
> > + if (offset == grbm_cntl || offset == grbm_idx) {
> > if (offset == grbm_cntl)
> > writel(v, scratch_reg2);
> > else if (offset == grbm_idx)
> > --
> > 2.26.0.rc1
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply [flat|nested] 7+ messages in thread