2021-12-04 22:02:57

by Arnd Bergmann

[permalink] [raw]
Subject: [PATCH] power: reset: ltc2952: fix float conversion error

From: Arnd Bergmann <[email protected]>

clang-14 does not like the way this driver converts a 'long double'
to an integer when the target architecture disables floating point
support:

drivers/power/reset/ltc2952-poweroff.c:162:28: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux' does not support it
data->wde_interval = 300L * 1E6L;
^

Turn this into pure integer math and make it more readable at the
same time using the NSEC_PER_MSEC macro instead.

Fixes: 6647156c00cc ("power: reset: add LTC2952 poweroff driver")
Signed-off-by: Arnd Bergmann <[email protected]>
---
drivers/power/reset/ltc2952-poweroff.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/power/reset/ltc2952-poweroff.c b/drivers/power/reset/ltc2952-poweroff.c
index fbb344353fe4..9fc88a9f244c 100644
--- a/drivers/power/reset/ltc2952-poweroff.c
+++ b/drivers/power/reset/ltc2952-poweroff.c
@@ -159,8 +159,8 @@ static void ltc2952_poweroff_kill(void)

static void ltc2952_poweroff_default(struct ltc2952_poweroff *data)
{
- data->wde_interval = 300L * 1E6L;
- data->trigger_delay = ktime_set(2, 500L*1E6L);
+ data->wde_interval = 300 * NSEC_PER_MSEC;
+ data->trigger_delay = ktime_set(2, 500 * NSEC_PER_MSEC);

hrtimer_init(&data->timer_trigger, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
data->timer_trigger.function = ltc2952_poweroff_timer_trigger;
--
2.29.2



2021-12-07 18:41:39

by Nick Desaulniers

[permalink] [raw]
Subject: Re: [PATCH] power: reset: ltc2952: fix float conversion error

On Sat, Dec 4, 2021 at 2:02 PM Arnd Bergmann <[email protected]> wrote:
>
> From: Arnd Bergmann <[email protected]>
>
> clang-14 does not like the way this driver converts a 'long double'
> to an integer when the target architecture disables floating point
> support:
>
> drivers/power/reset/ltc2952-poweroff.c:162:28: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux' does not support it
> data->wde_interval = 300L * 1E6L;
> ^
>
> Turn this into pure integer math and make it more readable at the
> same time using the NSEC_PER_MSEC macro instead.
>
> Fixes: 6647156c00cc ("power: reset: add LTC2952 poweroff driver")
> Signed-off-by: Arnd Bergmann <[email protected]>

Thanks for the patch! The change in clang-14 (ToT) that triggered this
has had another patch on top reverting these diagnostics.
https://reviews.llvm.org/D114162

That said, this change is still worthwhile for the improved semantics, IMO.

Link: https://github.com/ClangBuiltLinux/linux/issues/1497
Reviewed-by: Nick Desaulniers <[email protected]>

> ---
> drivers/power/reset/ltc2952-poweroff.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/power/reset/ltc2952-poweroff.c b/drivers/power/reset/ltc2952-poweroff.c
> index fbb344353fe4..9fc88a9f244c 100644
> --- a/drivers/power/reset/ltc2952-poweroff.c
> +++ b/drivers/power/reset/ltc2952-poweroff.c
> @@ -159,8 +159,8 @@ static void ltc2952_poweroff_kill(void)
>
> static void ltc2952_poweroff_default(struct ltc2952_poweroff *data)
> {
> - data->wde_interval = 300L * 1E6L;
> - data->trigger_delay = ktime_set(2, 500L*1E6L);
> + data->wde_interval = 300 * NSEC_PER_MSEC;
> + data->trigger_delay = ktime_set(2, 500 * NSEC_PER_MSEC);
>
> hrtimer_init(&data->timer_trigger, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
> data->timer_trigger.function = ltc2952_poweroff_timer_trigger;
> --
> 2.29.2
>


--
Thanks,
~Nick Desaulniers

2021-12-07 19:01:05

by Nick Desaulniers

[permalink] [raw]
Subject: Re: [PATCH] power: reset: ltc2952: fix float conversion error

On Tue, Dec 7, 2021 at 10:41 AM Nick Desaulniers
<[email protected]> wrote:
>
> On Sat, Dec 4, 2021 at 2:02 PM Arnd Bergmann <[email protected]> wrote:
> >
> > From: Arnd Bergmann <[email protected]>
> >
> > clang-14 does not like the way this driver converts a 'long double'
> > to an integer when the target architecture disables floating point
> > support:
> >
> > drivers/power/reset/ltc2952-poweroff.c:162:28: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux' does not support it
> > data->wde_interval = 300L * 1E6L;
> > ^
> >
> > Turn this into pure integer math and make it more readable at the
> > same time using the NSEC_PER_MSEC macro instead.
> >
> > Fixes: 6647156c00cc ("power: reset: add LTC2952 poweroff driver")
> > Signed-off-by: Arnd Bergmann <[email protected]>
>
> Thanks for the patch! The change in clang-14 (ToT) that triggered this
> has had another patch on top reverting these diagnostics.
> https://reviews.llvm.org/D114162
>
> That said, this change is still worthwhile for the improved semantics, IMO.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1497
> Reviewed-by: Nick Desaulniers <[email protected]>

Ah, a fix has already been picked up:
https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git/commit/?id=644106cdb89844be2496b21175b7c0c2e0fab381

>
> > ---
> > drivers/power/reset/ltc2952-poweroff.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/power/reset/ltc2952-poweroff.c b/drivers/power/reset/ltc2952-poweroff.c
> > index fbb344353fe4..9fc88a9f244c 100644
> > --- a/drivers/power/reset/ltc2952-poweroff.c
> > +++ b/drivers/power/reset/ltc2952-poweroff.c
> > @@ -159,8 +159,8 @@ static void ltc2952_poweroff_kill(void)
> >
> > static void ltc2952_poweroff_default(struct ltc2952_poweroff *data)
> > {
> > - data->wde_interval = 300L * 1E6L;
> > - data->trigger_delay = ktime_set(2, 500L*1E6L);
> > + data->wde_interval = 300 * NSEC_PER_MSEC;
> > + data->trigger_delay = ktime_set(2, 500 * NSEC_PER_MSEC);
> >
> > hrtimer_init(&data->timer_trigger, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
> > data->timer_trigger.function = ltc2952_poweroff_timer_trigger;
> > --
> > 2.29.2
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers



--
Thanks,
~Nick Desaulniers

2021-12-07 19:06:07

by Nathan Chancellor

[permalink] [raw]
Subject: Re: [PATCH] power: reset: ltc2952: fix float conversion error

On Tue, Dec 07, 2021 at 10:41:24AM -0800, Nick Desaulniers wrote:
> On Sat, Dec 4, 2021 at 2:02 PM Arnd Bergmann <[email protected]> wrote:
> >
> > From: Arnd Bergmann <[email protected]>
> >
> > clang-14 does not like the way this driver converts a 'long double'
> > to an integer when the target architecture disables floating point
> > support:
> >
> > drivers/power/reset/ltc2952-poweroff.c:162:28: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux' does not support it
> > data->wde_interval = 300L * 1E6L;
> > ^
> >
> > Turn this into pure integer math and make it more readable at the
> > same time using the NSEC_PER_MSEC macro instead.
> >
> > Fixes: 6647156c00cc ("power: reset: add LTC2952 poweroff driver")
> > Signed-off-by: Arnd Bergmann <[email protected]>
>
> Thanks for the patch! The change in clang-14 (ToT) that triggered this
> has had another patch on top reverting these diagnostics.
> https://reviews.llvm.org/D114162

I can still reproduce this failure on current ToT (33e3554ea33d) on
x86_64 allmodconfig; it seems like that patch only fixes it for 32-bit
x86.

> That said, this change is still worthwhile for the improved semantics, IMO.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1497
> Reviewed-by: Nick Desaulniers <[email protected]>

My patch appears to be accepted in Sebastian's branch already, it seems
like it just needs to be sent to Linus (it also looks like that branch
doesn't flow into -next, it probably should):

https://git.kernel.org/sre/linux-power-supply/c/644106cdb89844be2496b21175b7c0c2e0fab381

Cheers,
Nathan

> > ---
> > drivers/power/reset/ltc2952-poweroff.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/power/reset/ltc2952-poweroff.c b/drivers/power/reset/ltc2952-poweroff.c
> > index fbb344353fe4..9fc88a9f244c 100644
> > --- a/drivers/power/reset/ltc2952-poweroff.c
> > +++ b/drivers/power/reset/ltc2952-poweroff.c
> > @@ -159,8 +159,8 @@ static void ltc2952_poweroff_kill(void)
> >
> > static void ltc2952_poweroff_default(struct ltc2952_poweroff *data)
> > {
> > - data->wde_interval = 300L * 1E6L;
> > - data->trigger_delay = ktime_set(2, 500L*1E6L);
> > + data->wde_interval = 300 * NSEC_PER_MSEC;
> > + data->trigger_delay = ktime_set(2, 500 * NSEC_PER_MSEC);
> >
> > hrtimer_init(&data->timer_trigger, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
> > data->timer_trigger.function = ltc2952_poweroff_timer_trigger;
> > --
> > 2.29.2
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers