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From: Rhyland Klein <rklein@nvidia.com>
To: Olof Johansson <olof@lixom.net>
Cc: Anton Vorontsov <cbou@mail.ru>,
	David Woodhouse <dwmw2@infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] sbs-battery: probe should try talking to the device
Date: Thu, 6 Sep 2012 14:35:30 -0400	[thread overview]
Message-ID: <5048ECF2.8050307@nvidia.com> (raw)
In-Reply-To: <1346956349-21980-1-git-send-email-olof@lixom.net>

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

  reply	other threads:[~2012-09-06 18:35 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-06 18:32 [PATCH] sbs-battery: probe should try talking to the device Olof Johansson
2012-09-06 18:35 ` Rhyland Klein [this message]
2012-09-20 21:59   ` Anton Vorontsov

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