Re: [PATCH 1/2] drm/v3d: Avoid -Wconstant-logical-operand in nsecs_to_jiffies_timeout()
Hi Maira,
On Thu, Jul 27, 2023 at 11:01:27AM -0300, Maira Canal wrote:
> Hi Nathan,
>
> On 7/18/23 18:44, Nathan Chancellor wrote:
> > A proposed update to clang's -Wconstant-logical-operand to warn when the
> > left hand side is a constant shows the following instance in
> > nsecs_to_jiffies_timeout() when NSEC_PER_SEC is not a multiple of HZ,
> > such as CONFIG_HZ=300:
> >
> >In file included from drivers/gpu/drm/v3d/v3d_debugfs.c:12:
> >drivers/gpu/drm/v3d/v3d_drv.h:343:24: warning: use of logical '&&' with
> > constant operand [-Wconstant-logical-operand]
> > 343 | if (NSEC_PER_SEC % HZ &&
> > | ~ ^
> >drivers/gpu/drm/v3d/v3d_drv.h:343:24: note: use '&' for a bitwise
> > operation
> > 343 | if (NSEC_PER_SEC % HZ &&
> > | ^~
> > | &
> >drivers/gpu/drm/v3d/v3d_drv.h:343:24: note: remove constant to silence
> > this warning
> >1 warning generated.
> >
> > Turn this into an explicit comparison against zero to make the
> > expression a boolean to make it clear this should be a logical check,
> > not a bitwise one.
> >
> > Link: https://reviews.llvm.org/D142609
> > Signed-off-by: Nathan Chancellor
>
> Reviewed-by: Maíra Canal
>
> Thanks for all the hard work with clang! Let me know if you need someone
> to push it to drm-misc-next.
Yes I will, I do not have drm commit rights. I think the i915 patch can
go to drm-misc as well with Tvrtko's ack. Thanks a lot for taking a
look!
Cheers,
Nathan
> Best Regards,
> - Maíra
>
> > ---
> > drivers/gpu/drm/v3d/v3d_drv.h | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h
> > index b74b1351bfc8..7f664a4b2a75 100644
> > --- a/drivers/gpu/drm/v3d/v3d_drv.h
> > +++ b/drivers/gpu/drm/v3d/v3d_drv.h
> > @@ -340,7 +340,7 @@ struct v3d_submit_ext {
> > static inline unsigned long nsecs_to_jiffies_timeout(const u64 n)
> > {
> > /* nsecs_to_jiffies64() does not guard against overflow */
> > - if (NSEC_PER_SEC % HZ &&
> > + if ((NSEC_PER_SEC % HZ) != 0 &&
> > div_u64(n, NSEC_PER_SEC) >= MAX_JIFFY_OFFSET / HZ)
> > return MAX_JIFFY_OFFSET;
> >
Re: [PATCH 1/2] drm/v3d: Avoid -Wconstant-logical-operand in nsecs_to_jiffies_timeout()
Hi Nathan,
On 7/18/23 18:44, Nathan Chancellor wrote:
A proposed update to clang's -Wconstant-logical-operand to warn when the
left hand side is a constant shows the following instance in
nsecs_to_jiffies_timeout() when NSEC_PER_SEC is not a multiple of HZ,
such as CONFIG_HZ=300:
In file included from drivers/gpu/drm/v3d/v3d_debugfs.c:12:
drivers/gpu/drm/v3d/v3d_drv.h:343:24: warning: use of logical '&&' with
constant operand [-Wconstant-logical-operand]
343 | if (NSEC_PER_SEC % HZ &&
| ~ ^
drivers/gpu/drm/v3d/v3d_drv.h:343:24: note: use '&' for a bitwise operation
343 | if (NSEC_PER_SEC % HZ &&
| ^~
| &
drivers/gpu/drm/v3d/v3d_drv.h:343:24: note: remove constant to silence this
warning
1 warning generated.
Turn this into an explicit comparison against zero to make the
expression a boolean to make it clear this should be a logical check,
not a bitwise one.
Link: https://reviews.llvm.org/D142609
Signed-off-by: Nathan Chancellor
Reviewed-by: Maíra Canal
Thanks for all the hard work with clang! Let me know if you need someone
to push it to drm-misc-next.
Best Regards,
- Maíra
---
drivers/gpu/drm/v3d/v3d_drv.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h
index b74b1351bfc8..7f664a4b2a75 100644
--- a/drivers/gpu/drm/v3d/v3d_drv.h
+++ b/drivers/gpu/drm/v3d/v3d_drv.h
@@ -340,7 +340,7 @@ struct v3d_submit_ext {
static inline unsigned long nsecs_to_jiffies_timeout(const u64 n)
{
/* nsecs_to_jiffies64() does not guard against overflow */
- if (NSEC_PER_SEC % HZ &&
+ if ((NSEC_PER_SEC % HZ) != 0 &&
div_u64(n, NSEC_PER_SEC) >= MAX_JIFFY_OFFSET / HZ)
return MAX_JIFFY_OFFSET;
Re: [PATCH 1/2] drm/v3d: Avoid -Wconstant-logical-operand in nsecs_to_jiffies_timeout()
On Tue, Jul 18, 2023 at 2:44 PM Nathan Chancellor wrote:
>
> A proposed update to clang's -Wconstant-logical-operand to warn when the
> left hand side is a constant shows the following instance in
> nsecs_to_jiffies_timeout() when NSEC_PER_SEC is not a multiple of HZ,
> such as CONFIG_HZ=300:
>
> In file included from drivers/gpu/drm/v3d/v3d_debugfs.c:12:
> drivers/gpu/drm/v3d/v3d_drv.h:343:24: warning: use of logical '&&' with
> constant operand [-Wconstant-logical-operand]
> 343 | if (NSEC_PER_SEC % HZ &&
> | ~ ^
> drivers/gpu/drm/v3d/v3d_drv.h:343:24: note: use '&' for a bitwise operation
> 343 | if (NSEC_PER_SEC % HZ &&
> | ^~
> | &
> drivers/gpu/drm/v3d/v3d_drv.h:343:24: note: remove constant to silence this
> warning
> 1 warning generated.
>
> Turn this into an explicit comparison against zero to make the
> expression a boolean to make it clear this should be a logical check,
> not a bitwise one.
>
> Link: https://reviews.llvm.org/D142609
> Signed-off-by: Nathan Chancellor
Thanks for the patch!
Reviewed-by: Nick Desaulniers
> ---
> drivers/gpu/drm/v3d/v3d_drv.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h
> index b74b1351bfc8..7f664a4b2a75 100644
> --- a/drivers/gpu/drm/v3d/v3d_drv.h
> +++ b/drivers/gpu/drm/v3d/v3d_drv.h
> @@ -340,7 +340,7 @@ struct v3d_submit_ext {
> static inline unsigned long nsecs_to_jiffies_timeout(const u64 n)
> {
> /* nsecs_to_jiffies64() does not guard against overflow */
> - if (NSEC_PER_SEC % HZ &&
> + if ((NSEC_PER_SEC % HZ) != 0 &&
> div_u64(n, NSEC_PER_SEC) >= MAX_JIFFY_OFFSET / HZ)
> return MAX_JIFFY_OFFSET;
>
>
> --
> 2.41.0
>
--
Thanks,
~Nick Desaulniers
[PATCH 1/2] drm/v3d: Avoid -Wconstant-logical-operand in nsecs_to_jiffies_timeout()
A proposed update to clang's -Wconstant-logical-operand to warn when the
left hand side is a constant shows the following instance in
nsecs_to_jiffies_timeout() when NSEC_PER_SEC is not a multiple of HZ,
such as CONFIG_HZ=300:
In file included from drivers/gpu/drm/v3d/v3d_debugfs.c:12:
drivers/gpu/drm/v3d/v3d_drv.h:343:24: warning: use of logical '&&' with
constant operand [-Wconstant-logical-operand]
343 | if (NSEC_PER_SEC % HZ &&
| ~ ^
drivers/gpu/drm/v3d/v3d_drv.h:343:24: note: use '&' for a bitwise operation
343 | if (NSEC_PER_SEC % HZ &&
| ^~
| &
drivers/gpu/drm/v3d/v3d_drv.h:343:24: note: remove constant to silence this
warning
1 warning generated.
Turn this into an explicit comparison against zero to make the
expression a boolean to make it clear this should be a logical check,
not a bitwise one.
Link: https://reviews.llvm.org/D142609
Signed-off-by: Nathan Chancellor
---
drivers/gpu/drm/v3d/v3d_drv.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h
index b74b1351bfc8..7f664a4b2a75 100644
--- a/drivers/gpu/drm/v3d/v3d_drv.h
+++ b/drivers/gpu/drm/v3d/v3d_drv.h
@@ -340,7 +340,7 @@ struct v3d_submit_ext {
static inline unsigned long nsecs_to_jiffies_timeout(const u64 n)
{
/* nsecs_to_jiffies64() does not guard against overflow */
- if (NSEC_PER_SEC % HZ &&
+ if ((NSEC_PER_SEC % HZ) != 0 &&
div_u64(n, NSEC_PER_SEC) >= MAX_JIFFY_OFFSET / HZ)
return MAX_JIFFY_OFFSET;
--
2.41.0
