linux-kernel - Re: [PATCH RESEND 13/13] platform/chrome: cros_ec_lightbar

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Date:   Fri, 23 Jun 2017 15:22:46 -0700
From:   Benson Leung <bleung@...gle.com>
To:     Enric Balletbo i Serra <enric.balletbo@...labora.com>,
        olof@...om.net, bleung@...omium.org, linux-kernel@...r.kernel.org
Cc:     lee.jones@...aro.org, Jeffery Yu <jefferyy@...dia.com>,
        Guenter Roeck <groeck@...omium.org>
Subject: Re: [PATCH RESEND 13/13] platform/chrome: cros_ec_lightbar - Avoid
 I2C xfer to EC during suspend

Hi Enric,

On 05/16/2017 09:13 AM, Enric Balletbo i Serra wrote:
> From: Jeffery Yu <jefferyy@...dia.com>
> 
> A Mutex lock in cros_ec_cmd_xfer which may be held by frozen
> Userspace thread during system suspending. So should not
> call this routine in suspend thread.
> 
> Signed-off-by: Jeffery Yu <jefferyy@...dia.com>
> Signed-off-by: Guenter Roeck <groeck@...omium.org>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@...labora.com>

Signed-off-by: Benson Leung <bleung@...omium.org>

Applied.
> ---
>  drivers/platform/chrome/cros_ec_dev.c      | 12 ++++--------
>  drivers/platform/chrome/cros_ec_lightbar.c | 13 +++++++++----
>  2 files changed, 13 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
> index 7c26223..b9bf086 100644
> --- a/drivers/platform/chrome/cros_ec_dev.c
> +++ b/drivers/platform/chrome/cros_ec_dev.c
> @@ -437,8 +437,7 @@ static int ec_device_probe(struct platform_device *pdev)
>  		cros_ec_sensors_register(ec);
>  
>  	/* Take control of the lightbar from the EC. */
> -	if (ec_has_lightbar(ec))
> -		lb_manual_suspend_ctrl(ec, 1);
> +	lb_manual_suspend_ctrl(ec, 1);
>  
>  	return 0;
>  
> @@ -452,8 +451,7 @@ static int ec_device_remove(struct platform_device *pdev)
>  	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
>  
>  	/* Let the EC take over the lightbar again. */
> -	if (ec_has_lightbar(ec))
> -		lb_manual_suspend_ctrl(ec, 0);
> +	lb_manual_suspend_ctrl(ec, 0);
>  
>  	cros_ec_debugfs_remove(ec);
>  
> @@ -472,8 +470,7 @@ static int ec_device_suspend(struct device *dev)
>  {
>  	struct cros_ec_dev *ec = dev_get_drvdata(dev);
>  
> -	if (ec_has_lightbar(ec))
> -		lb_suspend(ec);
> +	lb_suspend(ec);
>  
>  	return 0;
>  }
> @@ -482,8 +479,7 @@ static int ec_device_resume(struct device *dev)
>  {
>  	struct cros_ec_dev *ec = dev_get_drvdata(dev);
>  
> -	if (ec_has_lightbar(ec))
> -		lb_resume(ec);
> +	lb_resume(ec);
>  
>  	return 0;
>  }
> diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c
> index e570c1e..fd2b047 100644
> --- a/drivers/platform/chrome/cros_ec_lightbar.c
> +++ b/drivers/platform/chrome/cros_ec_lightbar.c
> @@ -43,6 +43,7 @@ static unsigned long lb_interval_jiffies = 50 * HZ / 1000;
>   * If this is true, we won't do anything during suspend/resume.
>   */
>  static bool userspace_control;
> +static struct cros_ec_dev *ec_with_lightbar;
>  
>  static ssize_t interval_msec_show(struct device *dev,
>  				  struct device_attribute *attr, char *buf)
> @@ -384,6 +385,9 @@ int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable)
>  	struct cros_ec_command *msg;
>  	int ret;
>  
> +	if (ec != ec_with_lightbar)
> +		return 0;
> +
>  	msg = alloc_lightbar_cmd_msg(ec);
>  	if (!msg)
>  		return -ENOMEM;
> @@ -413,7 +417,7 @@ int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable)
>  
>  int lb_suspend(struct cros_ec_dev *ec)
>  {
> -	if (userspace_control)
> +	if (userspace_control || ec != ec_with_lightbar)
>  		return 0;
>  
>  	return lb_send_empty_cmd(ec, LIGHTBAR_CMD_SUSPEND);
> @@ -421,7 +425,7 @@ int lb_suspend(struct cros_ec_dev *ec)
>  
>  int lb_resume(struct cros_ec_dev *ec)
>  {
> -	if (userspace_control)
> +	if (userspace_control || ec != ec_with_lightbar)
>  		return 0;
>  
>  	return lb_send_empty_cmd(ec, LIGHTBAR_CMD_RESUME);
> @@ -606,9 +610,10 @@ static umode_t cros_ec_lightbar_attrs_are_visible(struct kobject *kobj,
>  		return 0;
>  
>  	/* Only instantiate this stuff if the EC has a lightbar */
> -	if (ec_has_lightbar(ec))
> +	if (ec_has_lightbar(ec)) {
> +		ec_with_lightbar = ec;
>  		return a->mode;
> -
> +	}
>  	return 0;
>  }
>  
> 

-- 
Benson Leung
Staff Software Engineer
Chrome OS Kernel
Google Inc.
bleung@...gle.com
Chromium OS Project
bleung@...omium.org



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