linux-kernel - Re: [PATCH 1/4] max17042: Move power suppply registration to a worker thread

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Date:	Tue, 29 Nov 2011 01:23:31 +0000 (GMT)
From:	MyungJoo Ham <myungjoo.ham@...sung.com>
To:	"dirk.brandewie@...il.com" <dirk.brandewie@...il.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Cc:	"cbouatmailru@...il.com" <cbouatmailru@...il.com>,
	김동근 <dg77.kim@...sung.com>,
	박경민 <kyungmin.park@...sung.com>,
	"Jason.Wortham@...im-ic.com" <Jason.Wortham@...im-ic.com>,
	"alan@...ux.intel.com" <alan@...ux.intel.com>
Subject: Re: [PATCH 1/4] max17042: Move power suppply registration to a worker
 thread

Sender : dirk.brandewie@...il.com<dirk.brandewie@...il.com>
Date : 2011-11-29 04:49 (GMT+09:00)
Title : [PATCH 1/4] max17042: Move power suppply registration to a worker thread
> 
> From: Dirk Brandewie 
> 
> This patch move the final registration of the battery to a worker
> thread in preperation for adding the POR proceedure recommended by
> maxim. This is needed since the Maxim init proceedure requires two
> long delays totaling 850ms. This patch will reduce the impact on
> system boot time.  The battery will not be available to the power
> supply subsystem until the init proceedure is complete
> 
> Signed-off-by: Dirk Brandewie 

Hello.

Could you please move "ret = power_supply_register(&client->dev, &chip->battery);" back to max17042_probe()?

That will enable other depending devices to probe without much concerning about synchronizing probe time.

For the data availability, max17042 can return -EAGAIN with its property function when its init function is not complete.


Cheers!
MyungJoo.

> ---
> drivers/power/max17042_battery.c |   53 +++++++++++++++++++++++---------------
> 1 files changed, 32 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
> index 9f0183c..33fdce0 100644
> --- a/drivers/power/max17042_battery.c
> +++ b/drivers/power/max17042_battery.c
> @@ -34,6 +34,7 @@ struct max17042_chip {
> struct i2c_client *client;
> struct power_supply battery;
> struct max17042_platform_data *pdata;
> + struct work_struct work;
> };
> 
> static int max17042_write_reg(struct i2c_client *client, u8 reg, u16 value)
> @@ -180,12 +181,40 @@ static int max17042_get_property(struct power_supply *psy,
> return 0;
> }
> 
> +static void max17042_init_worker(struct work_struct *work)
> +{
> + struct max17042_chip *chip = container_of(work,
> + struct max17042_chip, work);
> + struct i2c_client *client = chip->client;
> + int ret;
> +
> +
> + /* Initialize registers according to values from the platform data */
> + if (chip->pdata->init_data)
> + max17042_set_reg(client, chip->pdata->init_data,
> + chip->pdata->num_init_data);
> +
> + if (!chip->pdata->enable_current_sense) {
> + max17042_write_reg(client, MAX17042_CGAIN, 0x0000);
> + max17042_write_reg(client, MAX17042_MiscCFG, 0x0003);
> + max17042_write_reg(client, MAX17042_LearnCFG, 0x0007);
> + } else {
> + if (chip->pdata->r_sns == 0)
> + chip->pdata->r_sns = MAX17042_DEFAULT_SNS_RESISTOR;
> + }
> +
> + ret = power_supply_register(&client->dev, &chip->battery);
> + if (ret) {
> + dev_err(&client->dev, "failed: power supply register ");
> + kfree(chip);
> + }
> +}
> +
> static int __devinit max17042_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
> struct max17042_chip *chip;
> - int ret;
> 
> if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
> return -EIO;
> @@ -210,26 +239,8 @@ static int __devinit max17042_probe(struct i2c_client *client,
> if (!chip->pdata->enable_current_sense)
> chip->battery.num_properties -= 2;
> 
> - ret = power_supply_register(&client->dev, &chip->battery);
> - if (ret) {
> - dev_err(&client->dev, "failed: power supply register ");
> - kfree(chip);
> - return ret;
> - }
> -
> - /* Initialize registers according to values from the platform data */
> - if (chip->pdata->init_data)
> - max17042_set_reg(client, chip->pdata->init_data,
> - chip->pdata->num_init_data);
> -
> - if (!chip->pdata->enable_current_sense) {
> - max17042_write_reg(client, MAX17042_CGAIN, 0x0000);
> - max17042_write_reg(client, MAX17042_MiscCFG, 0x0003);
> - max17042_write_reg(client, MAX17042_LearnCFG, 0x0007);
> - } else {
> - if (chip->pdata->r_sns == 0)
> - chip->pdata->r_sns = MAX17042_DEFAULT_SNS_RESISTOR;
> - }
> + INIT_WORK(&chip->work, max17042_init_worker);
> + schedule_work(&chip->work);
> 
> return 0;
> }
> -- 
> 1.7.7.3
> 
> 




 MyungJoo Ham (함명주)

Mobile Software Platform Lab,
Digital Media and Communications (DMC) Business
Samsung Electronics
cell: +82-10-6714-2858 / office: +82-31-279-8033