| Message ID | 20211105152049.2522250-1-nathan@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | [v2] power: reset: ltc2952: Fix use of floating point literals | expand |
Hi, On Fri, Nov 05, 2021 at 08:20:50AM -0700, Nathan Chancellor wrote: > A new commit in LLVM causes an error on the use of 'long double' when > '-mno-x87' is used, which the kernel does through an alias, > '-mno-80387' (see the LLVM commit below for more details around why it > does this). > > drivers/power/reset/ltc2952-poweroff.c:162:28: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it > data->wde_interval = 300L * 1E6L; > ^ > drivers/power/reset/ltc2952-poweroff.c:162:21: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it > data->wde_interval = 300L * 1E6L; > ^ > drivers/power/reset/ltc2952-poweroff.c:163:41: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it > data->trigger_delay = ktime_set(2, 500L*1E6L); > ^ > 3 errors generated. > > This happens due to the use of a 'long double' literal. The 'E6' part of > '1E6L' causes the literal to be a 'double' then the 'L' suffix promotes > it to 'long double'. > > There is no visible reason for floating point values in this driver, as > the values are only assigned to integer types. Use NSEC_PER_MSEC, which > is the same integer value as '1E6L', to avoid changing functionality but > fix the error. > > Fixes: 6647156c00cc ("power: reset: add LTC2952 poweroff driver") > Link: https://github.com/ClangBuiltLinux/linux/issues/1497 > Link: https://github.com/llvm/llvm-project/commit/a8083d42b1c346e21623a1d36d1f0cadd7801d83 > Signed-off-by: Nathan Chancellor <nathan@kernel.org> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > --- Thanks, queued to power-supply's fixes branch. -- Sebastian > > v1 -> v2: https://lore.kernel.org/r/20211104215047.663411-1-nathan@kernel.org/ > > * A separate review pointed out that NSEC_PER_MSEC is a better choice > than USEC_PER_SEC because ktime_t is nanoseconds and the few functions > that take these values work in nanoseconds. The value is the same but > the documentation is better. > > * Pick up Nick's review tag. > > 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..65d9528cc989 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 = 300L * NSEC_PER_MSEC; > + data->trigger_delay = ktime_set(2, 500L * NSEC_PER_MSEC); > > hrtimer_init(&data->timer_trigger, CLOCK_MONOTONIC, HRTIMER_MODE_REL); > data->timer_trigger.function = ltc2952_poweroff_timer_trigger; > > base-commit: d4439a1189f93d0ac1eaf0197db8e6b3e197d5c7 > -- > 2.34.0.rc0 >
Hi Sebastian, On Tue, Nov 16, 2021 at 03:26:14PM +0100, Sebastian Reichel wrote: > Hi, > > On Fri, Nov 05, 2021 at 08:20:50AM -0700, Nathan Chancellor wrote: > > A new commit in LLVM causes an error on the use of 'long double' when > > '-mno-x87' is used, which the kernel does through an alias, > > '-mno-80387' (see the LLVM commit below for more details around why it > > does this). > > > > drivers/power/reset/ltc2952-poweroff.c:162:28: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it > > data->wde_interval = 300L * 1E6L; > > ^ > > drivers/power/reset/ltc2952-poweroff.c:162:21: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it > > data->wde_interval = 300L * 1E6L; > > ^ > > drivers/power/reset/ltc2952-poweroff.c:163:41: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it > > data->trigger_delay = ktime_set(2, 500L*1E6L); > > ^ > > 3 errors generated. > > > > This happens due to the use of a 'long double' literal. The 'E6' part of > > '1E6L' causes the literal to be a 'double' then the 'L' suffix promotes > > it to 'long double'. > > > > There is no visible reason for floating point values in this driver, as > > the values are only assigned to integer types. Use NSEC_PER_MSEC, which > > is the same integer value as '1E6L', to avoid changing functionality but > > fix the error. > > > > Fixes: 6647156c00cc ("power: reset: add LTC2952 poweroff driver") > > Link: https://github.com/ClangBuiltLinux/linux/issues/1497 > > Link: https://github.com/llvm/llvm-project/commit/a8083d42b1c346e21623a1d36d1f0cadd7801d83 > > Signed-off-by: Nathan Chancellor <nathan@kernel.org> > > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > > --- > > Thanks, queued to power-supply's fixes branch. Is there a timeline for getting this to Linus, since it has been a month and a half now since this was applied? It breaks several x86_64 configs with tip of tree clang, which harms our testing of the upcoming release, and other people are now tripping over this and reporting it on the LLVM issue tracker: https://github.com/llvm/llvm-project/issues/52924 Also, I noticed that your fixes branch is not flowing into linux-next, meaning this is not fixed there either. Would it be possible for you to ask Stephen Rothwell to add it? Cheers, Nathan > > > > v1 -> v2: https://lore.kernel.org/r/20211104215047.663411-1-nathan@kernel.org/ > > > > * A separate review pointed out that NSEC_PER_MSEC is a better choice > > than USEC_PER_SEC because ktime_t is nanoseconds and the few functions > > that take these values work in nanoseconds. The value is the same but > > the documentation is better. > > > > * Pick up Nick's review tag. > > > > 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..65d9528cc989 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 = 300L * NSEC_PER_MSEC; > > + data->trigger_delay = ktime_set(2, 500L * NSEC_PER_MSEC); > > > > hrtimer_init(&data->timer_trigger, CLOCK_MONOTONIC, HRTIMER_MODE_REL); > > data->timer_trigger.function = ltc2952_poweroff_timer_trigger; > > > > base-commit: d4439a1189f93d0ac1eaf0197db8e6b3e197d5c7 > > -- > > 2.34.0.rc0 > >
diff --git a/drivers/power/reset/ltc2952-poweroff.c b/drivers/power/reset/ltc2952-poweroff.c index fbb344353fe4..65d9528cc989 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 = 300L * NSEC_PER_MSEC; + data->trigger_delay = ktime_set(2, 500L * NSEC_PER_MSEC); hrtimer_init(&data->timer_trigger, CLOCK_MONOTONIC, HRTIMER_MODE_REL); data->timer_trigger.function = ltc2952_poweroff_timer_trigger;
A new commit in LLVM causes an error on the use of 'long double' when '-mno-x87' is used, which the kernel does through an alias, '-mno-80387' (see the LLVM commit below for more details around why it does this). drivers/power/reset/ltc2952-poweroff.c:162:28: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it data->wde_interval = 300L * 1E6L; ^ drivers/power/reset/ltc2952-poweroff.c:162:21: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it data->wde_interval = 300L * 1E6L; ^ drivers/power/reset/ltc2952-poweroff.c:163:41: error: expression requires 'long double' type support, but target 'x86_64-unknown-linux-gnu' does not support it data->trigger_delay = ktime_set(2, 500L*1E6L); ^ 3 errors generated. This happens due to the use of a 'long double' literal. The 'E6' part of '1E6L' causes the literal to be a 'double' then the 'L' suffix promotes it to 'long double'. There is no visible reason for floating point values in this driver, as the values are only assigned to integer types. Use NSEC_PER_MSEC, which is the same integer value as '1E6L', to avoid changing functionality but fix the error. Fixes: 6647156c00cc ("power: reset: add LTC2952 poweroff driver") Link: https://github.com/ClangBuiltLinux/linux/issues/1497 Link: https://github.com/llvm/llvm-project/commit/a8083d42b1c346e21623a1d36d1f0cadd7801d83 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> --- v1 -> v2: https://lore.kernel.org/r/20211104215047.663411-1-nathan@kernel.org/ * A separate review pointed out that NSEC_PER_MSEC is a better choice than USEC_PER_SEC because ktime_t is nanoseconds and the few functions that take these values work in nanoseconds. The value is the same but the documentation is better. * Pick up Nick's review tag. drivers/power/reset/ltc2952-poweroff.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) base-commit: d4439a1189f93d0ac1eaf0197db8e6b3e197d5c7