Re: [PATCH v3 06/16] tpm-chip: utilize new cdev_device_add helper function

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

On Mon, Mar 06, 2017 at 12:04:22AM -0700, Logan Gunthorpe wrote:
> Replace the open coded registration of the cdev and dev with the
> new device_add_cdev() helper. The helper replaces a common pattern by
> taking the proper reference against the parent device and adding both
> the cdev and the device.
> 
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
> ---
>  drivers/char/tpm/tpm-chip.c | 19 +++----------------
>  1 file changed, 3 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index c406343..935f0e9 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -187,7 +187,6 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev,
>  
>  	cdev_init(&chip->cdev, &tpm_fops);
>  	chip->cdev.owner = THIS_MODULE;
> -	chip->cdev.kobj.parent = &chip->dev.kobj;
>  
>  	return chip;
>  
> @@ -230,27 +229,16 @@ static int tpm_add_char_device(struct tpm_chip *chip)
>  {
>  	int rc;
>  
> -	rc = cdev_add(&chip->cdev, chip->dev.devt, 1);
> +	rc = cdev_device_add(&chip->cdev, &chip->dev);
>  	if (rc) {
>  		dev_err(&chip->dev,
> -			"unable to cdev_add() %s, major %d, minor %d, err=%d\n",
> +			"unable to cdev_device_add() %s, major %d, minor %d, err=%d\n",
>  			dev_name(&chip->dev), MAJOR(chip->dev.devt),
>  			MINOR(chip->dev.devt), rc);
>  
>  		return rc;
>  	}
>  
> -	rc = device_add(&chip->dev);
> -	if (rc) {
> -		dev_err(&chip->dev,
> -			"unable to device_register() %s, major %d, minor %d, err=%d\n",
> -			dev_name(&chip->dev), MAJOR(chip->dev.devt),
> -			MINOR(chip->dev.devt), rc);
> -
> -		cdev_del(&chip->cdev);
> -		return rc;
> -	}
> -
>  	/* Make the chip available. */
>  	mutex_lock(&idr_lock);
>  	idr_replace(&dev_nums_idr, chip, chip->dev_num);
> @@ -261,8 +249,7 @@ static int tpm_add_char_device(struct tpm_chip *chip)
>  
>  static void tpm_del_char_device(struct tpm_chip *chip)
>  {
> -	cdev_del(&chip->cdev);
> -	device_del(&chip->dev);
> +	cdev_device_del(&chip->cdev, &chip->dev);
>  
>  	/* Make the chip unavailable. */
>  	mutex_lock(&idr_lock);
> -- 
> 2.1.4
> 

Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

I cannot test this at this point as security tree does not include
the commit that is dependent on this. I'm also wondering if this
commit is even going through my tree to upstream?

/Jarkko