Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1665096

Re: [PATCH 1/2] power: supply: sbs-battery: Prevent CAPACITY_MODE races

Path csiph.com!news.mixmin.net!news.unit0.net!news.panservice.it!diesel.cu.mi.it!bofh.it!news.nic.it!robomod
From Guenter Roeck <groeck@google.com>
Newsgroups linux.kernel
Subject Re: [PATCH 1/2] power: supply: sbs-battery: Prevent CAPACITY_MODE races
Date Tue, 13 Jun 2017 20:20:02 +0200
Message-ID <tRYA2-2SW-13@gated-at.bofh.it> (permalink)
References <tRYgG-2x8-29@gated-at.bofh.it>
Dkim-Signature v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=aBcv4s5EHrWvyxe5dy6JwTkR9cc7NmK2Hr9dYC9pjhM=; b=ms7fMMe1hxshSNYXp4LDLSMi5cYcr2cSNfTKRjDgOVJoZEkRDOqDDWHUkdh+a5+5OF z4tB1K6R2JiEgv19ri9dppQ2a+jSZrbkPEYKOlF+/y+pubp8hEtSJwG0kPaLxiEdLkMX kC72d76rGUPrXAbuCNrIBYlzzzB4vphrE/W1bnrgHaQ0O2tZ+wMeo5xH8q9MwA+DWsBC SXdaJK2hUjJKsQx9U4R1So0lsUWjSeDoItHjBGdteTK4Wy4iompzqRLYhg8AFrHYyO3Z cLuMG0UYzxBju+jWocOQ9TM8G9h1UVocS8xohRD6l8GJ5Ks+ckxMfB7ayKi4rf5o4+N3 1W4A==
X-Google-Dkim-Signature v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=aBcv4s5EHrWvyxe5dy6JwTkR9cc7NmK2Hr9dYC9pjhM=; b=SdaVwkBidqHzTP9koxYgt1JPojg5T78Vu80MdQoie2Vrol31DDW7739GQDChlSW4t5 gliyXn0zZS076YipSlG8ZX54usHATcKAcXdDZEl4jF49Q4CaOv/Qv/GBGqxR6Vr2hmRU jWESDA1LyP7dM+btItrsnivKEXL5QopTMBY53yAIqf6EdLkuiYlWqYwXcVxORPJ6rVtf eZoW7n5i20tFoQQRBRGP/a0+pF3UfULNG1AWA+9/cDmcXbzbzoF80WMxzIBPBNvy4x6b 8wbzTyPycZo2MS7KUwhx6bn2FUKdTTE8jxAHK3KnSgbWxc1MTIs5IW2HPX6SaEv4Lorr N7QA==
X-Gm-Message-State AKS2vOyRP2r6gMZU9IJl82tmFBnc5JUOHL3+siiHwhOJDZPgOV4XFifz 0PD1i1E2fNfHzLJJLmwLdUh70YzpUxaC
X-Received by 10.55.175.199 with SMTP id y190mr1295693qke.155.1497377724311; Tue, 13 Jun 2017 11:15:24 -0700 (PDT)
MIME-Version 1.0
Content-Type text/plain; charset="UTF-8"
Sender robomod@news.nic.it
List-ID <linux-kernel.vger.kernel.org>
X-Mailing-List linux-kernel@vger.kernel.org
Approved robomod@news.nic.it
Lines 52
Organization linux.* mail to news gateway
X-Original-Cc Sebastian Reichel <sre@kernel.org>, linux-pm@vger.kernel.org, linux-kernel <linux-kernel@vger.kernel.org>, Guenter Roeck <groeck@chromium.org>
X-Original-Date Tue, 13 Jun 2017 11:15:23 -0700
X-Original-Message-ID <CABXOdTf=ObbPUaZp+zvBGaKqvifbLSTcZcnzWQt80xGcvusyYg@mail.gmail.com>
X-Original-References <1497376406-86470-1-git-send-email-shawnn@chromium.org>
X-Original-Sender linux-kernel-owner@vger.kernel.org
Xref csiph.com linux.kernel:1665096

Show key headers only | View raw


On Tue, Jun 13, 2017 at 10:53 AM, Shawn Nematbakhsh <shawnn@chromium.org> wrote:
> A subset of smart battery commands return charge or energy depending on
> the CAPACITY_MODE bit setting of BatteryMode(). In order to
> unambiguously read a charge or energy value, it is necessary to ensure
> that CAPACITY_MODE is set as desired, and not changed for the duration
> of the attribute read.
>
> Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>

Reviewed-by: Guenter Roeck <groeck@chromium.org>

> ---
>  drivers/power/supply/sbs-battery.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/drivers/power/supply/sbs-battery.c b/drivers/power/supply/sbs-battery.c
> index e3a114e60f1a..d7e68fd97099 100644
> --- a/drivers/power/supply/sbs-battery.c
> +++ b/drivers/power/supply/sbs-battery.c
> @@ -171,6 +171,7 @@ struct sbs_info {
>         u32                             i2c_retry_count;
>         u32                             poll_retry_count;
>         struct delayed_work             work;
> +       struct mutex                    mode_lock;
>  };
>
>  static char model_name[I2C_SMBUS_BLOCK_MAX + 1];
> @@ -623,7 +624,13 @@ static int sbs_get_property(struct power_supply *psy,
>                 if (ret < 0)
>                         break;
>
> +               /* sbs_get_battery_capacity() will change the battery mode
> +                * temporarily to read the requested attribute. Ensure we stay
> +                * in the desired mode for the duration of the attribute read.
> +                */
> +               mutex_lock(&chip->mode_lock);
>                 ret = sbs_get_battery_capacity(client, ret, psp, val);
> +               mutex_unlock(&chip->mode_lock);
>                 break;
>
>         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
> @@ -808,6 +815,7 @@ static int sbs_probe(struct i2c_client *client,
>         psy_cfg.of_node = client->dev.of_node;
>         psy_cfg.drv_data = chip;
>         chip->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
> +       mutex_init(&chip->mode_lock);
>
>         /* use pdata if available, fall back to DT properties,
>          * or hardcoded defaults if not
> --
> 2.13.1.508.gb3defc5cc-goog
>

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH 1/2] power: supply: sbs-battery: Prevent CAPACITY_MODE races Shawn Nematbakhsh <shawnn@chromium.org> - 2017-06-13 20:00 +0200
  Re: [PATCH 1/2] power: supply: sbs-battery: Prevent CAPACITY_MODE races Guenter Roeck <groeck@google.com> - 2017-06-13 20:20 +0200
  Re: [PATCH 1/2] power: supply: sbs-battery: Prevent CAPACITY_MODE  races Sebastian Reichel <sebastian.reichel@collabora.co.uk> - 2017-06-15 18:50 +0200

csiph-web