lkml.org 
[lkml]   [2021]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
SubjectRe: [PATCH] soc/tegra: fuse: Fix bitwise vs. logical OR warning
+ Anders (combining
https://lore.kernel.org/all/20211117142115.694316-1-anders.roxell@linaro.org/).

On Thu, Oct 21, 2021 at 2:45 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> A new warning in clang points out two instances where boolean
> expressions are being used with a bitwise OR instead of logical OR:
>
> drivers/soc/tegra/fuse/speedo-tegra20.c:72:9: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical]
> reg = tegra_fuse_read_spare(i) |
> ^~~~~~~~~~~~~~~~~~~~~~~~~~
> ||
> drivers/soc/tegra/fuse/speedo-tegra20.c:72:9: note: cast one or both operands to int to silence this warning
> drivers/soc/tegra/fuse/speedo-tegra20.c:87:9: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical]
> reg = tegra_fuse_read_spare(i) |
> ^~~~~~~~~~~~~~~~~~~~~~~~~~
> ||
> drivers/soc/tegra/fuse/speedo-tegra20.c:87:9: note: cast one or both operands to int to silence this warning
> 2 warnings generated.
>
> The motivation for the warning is that logical operations short circuit
> while bitwise operations do not. In this case, it does not seem like
> short circuiting is harmful so implement the suggested fix of changing
> to a logical operation to fix the warning.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1488
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Fixes: 25cd5a391478 ("ARM: tegra: Add speedo-based process identification")

> ---
> drivers/soc/tegra/fuse/speedo-tegra20.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/soc/tegra/fuse/speedo-tegra20.c b/drivers/soc/tegra/fuse/speedo-tegra20.c
> index 2546bddbab93..4984246605ae 100644
> --- a/drivers/soc/tegra/fuse/speedo-tegra20.c
> +++ b/drivers/soc/tegra/fuse/speedo-tegra20.c
> @@ -69,7 +69,7 @@ void __init tegra20_init_speedo_data(struct tegra_sku_info *sku_info)
>
> val = 0;
> for (i = CPU_SPEEDO_MSBIT; i >= CPU_SPEEDO_LSBIT; i--) {
> - reg = tegra_fuse_read_spare(i) |
> + reg = tegra_fuse_read_spare(i) ||
> tegra_fuse_read_spare(i + CPU_SPEEDO_REDUND_OFFS);
> val = (val << 1) | (reg & 0x1);
> }
> @@ -84,7 +84,7 @@ void __init tegra20_init_speedo_data(struct tegra_sku_info *sku_info)
>
> val = 0;
> for (i = SOC_SPEEDO_MSBIT; i >= SOC_SPEEDO_LSBIT; i--) {
> - reg = tegra_fuse_read_spare(i) |
> + reg = tegra_fuse_read_spare(i) ||
> tegra_fuse_read_spare(i + SOC_SPEEDO_REDUND_OFFS);
> val = (val << 1) | (reg & 0x1);
> }
>
> base-commit: 519d81956ee277b4419c723adfb154603c2565ba
> --
> 2.33.1.637.gf443b226ca
>


--
Thanks,
~Nick Desaulniers

\
 
 \ /
  Last update: 2021-11-17 19:21    [W:0.212 / U:0.508 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site