[PATCH] sbs-battery: probe should try talking to the device

[PATCH] sbs-battery: probe should try talking to the device

[Olof Johansson]

Turns out this driver doesn't actually try talking to the device at
probe time, so if it's incorrectly configured in the device tree or
platform data (or if the battery has been removed from the system), then
probe will succeed and every access will sit there and time out. The
end result is a possibly laggy system that thinks it has a battery but
can never read status, which isn't very useful.

Instead, just read any register (I chose status) at probe, and if that
fails, don't register the device.

Signed-off-by: Olof Johansson <olof@lixom.net>
---
 drivers/power/sbs-battery.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/power/sbs-battery.c b/drivers/power/sbs-battery.c
index a65e8f5..2f24253 100644
--- a/drivers/power/sbs-battery.c
+++ b/drivers/power/sbs-battery.c
@@ -760,6 +760,16 @@ static int __devinit sbs_probe(struct i2c_client *client,
 
 skip_gpio:
 
+	/* Before we register, we need to make sure we can actually talk
+	 * to the battery.
+	 */
+	rc = sbs_read_word_data(client, sbs_data[REG_STATUS].addr);
+	if (rc < 0) {
+		dev_err(&client->dev, "%s: Failed to get device status\n",
+			__func__);
+		goto exit_psupply;
+	}
+
 	rc = power_supply_register(&client->dev, &chip->power_supply);
 	if (rc) {
 		dev_err(&client->dev,
-- 
1.7.10.1.488.g05fbf7a

Re: [PATCH] sbs-battery: probe should try talking to the device

[Rhyland Klein]

On 09/06/2012 02:32 PM, Olof Johansson wrote:
> Turns out this driver doesn't actually try talking to the device at
> probe time, so if it's incorrectly configured in the device tree or
> platform data (or if the battery has been removed from the system), then
> probe will succeed and every access will sit there and time out. The
> end result is a possibly laggy system that thinks it has a battery but
> can never read status, which isn't very useful.
>
> Instead, just read any register (I chose status) at probe, and if that
> fails, don't register the device.
>
> Signed-off-by: Olof Johansson <olof@lixom.net>
> ---
>   drivers/power/sbs-battery.c | 10 ++++++++++
>   1 file changed, 10 insertions(+)
>
> diff --git a/drivers/power/sbs-battery.c b/drivers/power/sbs-battery.c
> index a65e8f5..2f24253 100644
> --- a/drivers/power/sbs-battery.c
> +++ b/drivers/power/sbs-battery.c
> @@ -760,6 +760,16 @@ static int __devinit sbs_probe(struct i2c_client *client,
>
>   skip_gpio:
>
> +	/* Before we register, we need to make sure we can actually talk
> +	 * to the battery.
> +	 */
> +	rc = sbs_read_word_data(client, sbs_data[REG_STATUS].addr);
> +	if (rc < 0) {
> +		dev_err(&client->dev, "%s: Failed to get device status\n",
> +			__func__);
> +		goto exit_psupply;
> +	}
> +
>   	rc = power_supply_register(&client->dev, &chip->power_supply);
>   	if (rc) {
>   		dev_err(&client->dev,
>

Acked-by: Rhyland Klein <rklein@nvidia.com>

-- 
nvpublic

Re: [PATCH] sbs-battery: probe should try talking to the device

[Anton Vorontsov]

On Thu, Sep 06, 2012 at 02:35:30PM -0400, Rhyland Klein wrote:
> On 09/06/2012 02:32 PM, Olof Johansson wrote:
> >Turns out this driver doesn't actually try talking to the device at
> >probe time, so if it's incorrectly configured in the device tree or
> >platform data (or if the battery has been removed from the system), then
> >probe will succeed and every access will sit there and time out. The
> >end result is a possibly laggy system that thinks it has a battery but
> >can never read status, which isn't very useful.
> >
> >Instead, just read any register (I chose status) at probe, and if that
> >fails, don't register the device.
> >
> >Signed-off-by: Olof Johansson <olof@lixom.net>
[...]
> Acked-by: Rhyland Klein <rklein@nvidia.com>

Applied, thank you folks!