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Groups > linux.kernel > #1665080 > unrolled thread
| Started by | Shawn Nematbakhsh <shawnn@chromium.org> |
|---|---|
| First post | 2017-06-13 20:00 +0200 |
| Last post | 2017-06-15 18:50 +0200 |
| Articles | 3 — 3 participants |
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[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
| From | Shawn Nematbakhsh <shawnn@chromium.org> |
|---|---|
| Date | 2017-06-13 20:00 +0200 |
| Subject | [PATCH 1/2] power: supply: sbs-battery: Prevent CAPACITY_MODE races |
| Message-ID | <tRYgG-2x8-29@gated-at.bofh.it> |
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>
---
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
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| From | Guenter Roeck <groeck@google.com> |
|---|---|
| Date | 2017-06-13 20:20 +0200 |
| Message-ID | <tRYA2-2SW-13@gated-at.bofh.it> |
| In reply to | #1665080 |
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
>
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| From | Sebastian Reichel <sebastian.reichel@collabora.co.uk> |
|---|---|
| Date | 2017-06-15 18:50 +0200 |
| Subject | Re: [PATCH 1/2] power: supply: sbs-battery: Prevent CAPACITY_MODE races |
| Message-ID | <tSG83-4QO-43@gated-at.bofh.it> |
| In reply to | #1665080 |
[Multipart message — attachments visible in raw view] — view raw
Hi,
On Tue, Jun 13, 2017 at 10:53:25AM -0700, Shawn Nematbakhsh 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>
> ---
Thanks, queued.
-- Sebastian
> 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
>
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