linux-kernel - [PATCH] power: supply: qcom_battmgr: remove bogus do

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 14 Feb 2023 14:20:42 +0100
From:   Arnd Bergmann <arnd@...nel.org>
To:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Sebastian Reichel <sre@...nel.org>
Cc:     Arnd Bergmann <arnd@...db.de>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        linux-arm-msm@...r.kernel.org, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] power: supply: qcom_battmgr: remove bogus do_div()

From: Arnd Bergmann <arnd@...db.de>

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@...db.de>
---
 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