Re: [PATCH] power: supply: qcom_battmgr: remove bogus do_div()

From: Nathan Chancellor
Date: Wed Mar 01 2023 - 13:16:45 EST


Hi Linus,

On Tue, Feb 14, 2023 at 02:20:42PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> The argument to do_div() is a 32-bit integer, and it was read from a
> 32-bit register so there is no point in doing a 64-bit division on it.
>
> On 32-bit arm, do_div() causes a compile-time warning here:
>
> include/asm-generic/div64.h:238:22: error: passing argument 1 of '__div64_32' from incompatible pointer type [-Werror=incompatible-pointer-types]
> 238 | __rem = __div64_32(&(n), __base); \
> | ^~~~
> | |
> | unsigned int *
> drivers/power/supply/qcom_battmgr.c:1130:4: note: in expansion of macro 'do_div'
> 1130 | do_div(battmgr->status.percent, 100);
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> drivers/power/supply/qcom_battmgr.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/power/supply/qcom_battmgr.c b/drivers/power/supply/qcom_battmgr.c
> index ec31f887184f..de77df97b3a4 100644
> --- a/drivers/power/supply/qcom_battmgr.c
> +++ b/drivers/power/supply/qcom_battmgr.c
> @@ -1126,8 +1126,7 @@ static void qcom_battmgr_sm8350_callback(struct qcom_battmgr *battmgr,
> battmgr->info.charge_type = le32_to_cpu(resp->intval.value);
> break;
> case BATT_CAPACITY:
> - battmgr->status.percent = le32_to_cpu(resp->intval.value);
> - do_div(battmgr->status.percent, 100);
> + battmgr->status.percent = le32_to_cpu(resp->intval.value) / 100;
> break;
> case BATT_VOLT_OCV:
> battmgr->status.voltage_ocv = le32_to_cpu(resp->intval.value);
> --
> 2.39.1
>

Would you be able to take this patch directly? It seems obviously
correctTM, has an ack from Sebastian [1], and without it, 32-bit
allmodconfig builds are broken [2] (the other warning in that log has a
fix on the way to you soon).

[1]: https://lore.kernel.org/20230214220210.cpviycsmcppylkgj@xxxxxxxxxxxxxxxxxxxxxx/
[2]: https://storage.tuxsuite.com/public/clangbuiltlinux/continuous-integration2/builds/2MPmxwvmQ7FdpiMhdQN2ZJhcoUP/build.log

Cheers,
Nathan