linux-kernel - Re: [PATCH 3/4] extcon: axp288: Redo charger type dection a couple of seconds after probe()

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Date:   Tue, 02 Jan 2018 09:54:37 +0900
From:   Chanwoo Choi <cw00.choi@...sung.com>
To:     Hans de Goede <hdegoede@...hat.com>,
        MyungJoo Ham <myungjoo.ham@...sung.com>
Cc:     linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/4] extcon: axp288: Redo charger type dection a couple
 of seconds after probe()

Hi Hans,

s/dection/detection on patch title.

On 2017년 12월 22일 21:36, Hans de Goede wrote:
> The axp288 extcon code depends on other drivers to do things like mux the
> data lines, enable/disable vbus based on the id-pin, etc.
> 
> Sometimes the BIOS has not set these things up correctly resulting in the
> initial charger cable type detection giving a wrong result and we end up
> not charging or charging at only 0.5A.
> 
> This commit starts a second charger-detection cycle a couple of seconds
> after the first one finishes, giving the other drivers time to load and
> do their thing.
> 
> Signed-off-by: Hans de Goede <hdegoede@...hat.com>
> ---
>  drivers/extcon/extcon-axp288.c | 32 ++++++++++++++++++++++++++++++--
>  1 file changed, 30 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/extcon/extcon-axp288.c b/drivers/extcon/extcon-axp288.c
> index 386afb7d1160..cc7c35c7ff02 100644
> --- a/drivers/extcon/extcon-axp288.c
> +++ b/drivers/extcon/extcon-axp288.c
> @@ -1,6 +1,7 @@
>  /*
>   * extcon-axp288.c - X-Power AXP288 PMIC extcon cable detection driver
>   *
> + * Copyright (C) 2016-2017 Hans de Goede <hdegoede@...hat.com>
>   * Copyright (C) 2015 Intel Corporation
>   * Author: Ramakrishna Pallala <ramakrishna.pallala@...el.com>
>   *
> @@ -97,9 +98,11 @@ struct axp288_extcon_info {
>  	struct device *dev;
>  	struct regmap *regmap;
>  	struct regmap_irq_chip_data *regmap_irqc;
> +	struct delayed_work det_work;
>  	int irq[EXTCON_IRQ_END];
>  	struct extcon_dev *edev;
>  	unsigned int previous_cable;
> +	bool first_detect_done;

The first_detect_done is used only one time in the axp288_handle_chrg_det_event().
The other function don't use it. So, you better to define and use
'static bool first_detect_done' in the axp288_handle_chrg_det_event()
instead of defining the 'first_detect_done' in the struct axp288_extcon_info.

>  };
>  
>  /* Power up/down reason string array */
> @@ -137,6 +140,25 @@ static void axp288_extcon_log_rsi(struct axp288_extcon_info *info)
>  	regmap_write(info->regmap, AXP288_PS_BOOT_REASON_REG, clear_mask);
>  }
>  
> +static void axp288_chrg_detect_complete(struct axp288_extcon_info *info)
> +{
> +	/*
> +	 * We depend on other drivers to do things like mux the data lines,
> +	 * enable/disable vbus based on the id-pin, etc. Sometimes the BIOS has
> +	 * not set these things up correctly resulting in the initial charger
> +	 * cable type detection giving a wrong result and we end up not charging
> +	 * or charging at only 0.5A.
> +	 *
> +	 * So we schedule a second cable type detection after 2 seconds to
> +	 * give the other drivers time to load and do their thing.
> +	 */
> +	if (!info->first_detect_done) {
> +		queue_delayed_work(system_wq, &info->det_work,
> +				   msecs_to_jiffies(2000));
> +		info->first_detect_done = true;
> +	}
> +}

The axp288_chrg_detect_complete() is only used in the axp288_handle_chrg_det_event()
and axp288_chrg_detect_complete() is not a complicate. I think that you don't need
to make the separate function. I'd like you to add the 

> +
>  static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info)
>  {
>  	int ret, stat, cfg, pwr_stat;
> @@ -201,6 +223,8 @@ static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info)
>  		info->previous_cable = cable;
>  	}
>  
> +	axp288_chrg_detect_complete(info);

As I commented, you better to add the code directly instead of separate function.

> +
>  	return 0;
>  
>  dev_det_ret:
> @@ -222,8 +246,11 @@ static irqreturn_t axp288_extcon_isr(int irq, void *data)
>  	return IRQ_HANDLED;
>  }
>  
> -static void axp288_extcon_enable(struct axp288_extcon_info *info)
> +static void axp288_extcon_det_work(struct work_struct *work)
>  {
> +	struct axp288_extcon_info *info =
> +		container_of(work, struct axp288_extcon_info, det_work.work);
> +
>  	regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,
>  						BC_GLOBAL_RUN, 0);
>  	/* Enable the charger detection logic */
> @@ -245,6 +272,7 @@ static int axp288_extcon_probe(struct platform_device *pdev)
>  	info->regmap = axp20x->regmap;
>  	info->regmap_irqc = axp20x->regmap_irqc;
>  	info->previous_cable = EXTCON_NONE;
> +	INIT_DELAYED_WORK(&info->det_work, axp288_extcon_det_work);
>  
>  	platform_set_drvdata(pdev, info);
>  
> @@ -287,7 +315,7 @@ static int axp288_extcon_probe(struct platform_device *pdev)
>  	}
>  
>  	/* Start charger cable type detection */
> -	axp288_extcon_enable(info);
> +	queue_delayed_work(system_wq, &info->det_work, 0);
>  
>  	return 0;
>  }
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics