Re: [PATCH] [media] lirc_dev: store cdev in irctl, up maxdevs

[Andy Walls <awalls@md.metrocast.net>]

On Fri, 2011-05-27 at 16:01 -0400, Jarod Wilson wrote:
> Store the cdev pointer in struct irctl, allocated dynamically as needed,
> rather than having a static array. At the same time, recycle some of the
> saved memory to nudge the maximum number of lirc devices supported up a
> ways -- its not that uncommon these days, now that we have the rc-core
> lirc bridge driver, to see a system with at least 4 raw IR receivers.
> (consider a mythtv backend with several video capture devices and the
> possible need for IR transmit hardware).
> 
> Signed-off-by: Jarod Wilson <jarod@redhat.com>
> ---
>  drivers/media/rc/lirc_dev.c |   33 ++++++++++++++++++++++++---------
>  include/media/lirc_dev.h    |    2 +-
>  2 files changed, 25 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
> index fd237ab..9e79692 100644
> --- a/drivers/media/rc/lirc_dev.c
> +++ b/drivers/media/rc/lirc_dev.c
> @@ -55,6 +55,8 @@ struct irctl {
>  	struct lirc_buffer *buf;
>  	unsigned int chunk_size;
>  
> +	struct cdev *cdev;
> +
>  	struct task_struct *task;
>  	long jiffies_to_wait;
>  };
> @@ -62,7 +64,6 @@ struct irctl {
>  static DEFINE_MUTEX(lirc_dev_lock);
>  
>  static struct irctl *irctls[MAX_IRCTL_DEVICES];
> -static struct cdev cdevs[MAX_IRCTL_DEVICES];
>  
>  /* Only used for sysfs but defined to void otherwise */
>  static struct class *lirc_class;
> @@ -169,7 +170,9 @@ static int lirc_cdev_add(struct irctl *ir)
>  {
>  	int retval;
>  	struct lirc_driver *d = &ir->d;
> -	struct cdev *cdev = &cdevs[d->minor];
> +	struct cdev *cdev;
> +
> +	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);

	if (cdev == NULL) 
		

>  	if (d->fops) {
>  		cdev_init(cdev, d->fops);

	   generate_oops();

;)

Regards,
Andy


> @@ -180,12 +183,20 @@ static int lirc_cdev_add(struct irctl *ir)
>  	}
>  	retval = kobject_set_name(&cdev->kobj, "lirc%d", d->minor);
>  	if (retval)
> -		return retval;
> +		goto err_out;
>  
>  	retval = cdev_add(cdev, MKDEV(MAJOR(lirc_base_dev), d->minor), 1);
> -	if (retval)
> +	if (retval) {
>  		kobject_put(&cdev->kobj);
> +		goto err_out;
> +	}
> +
> +	ir->cdev = cdev;
> +
> +	return 0;
>  
> +err_out:
> +	kfree(cdev);
>  	return retval;
>  }
>  
> @@ -214,7 +225,7 @@ int lirc_register_driver(struct lirc_driver *d)
>  	if (MAX_IRCTL_DEVICES <= d->minor) {
>  		dev_err(d->dev, "lirc_dev: lirc_register_driver: "
>  			"\"minor\" must be between 0 and %d (%d)!\n",
> -			MAX_IRCTL_DEVICES-1, d->minor);
> +			MAX_IRCTL_DEVICES - 1, d->minor);
>  		err = -EBADRQC;
>  		goto out;
>  	}
> @@ -369,7 +380,7 @@ int lirc_unregister_driver(int minor)
>  
>  	if (minor < 0 || minor >= MAX_IRCTL_DEVICES) {
>  		printk(KERN_ERR "lirc_dev: %s: minor (%d) must be between "
> -		       "0 and %d!\n", __func__, minor, MAX_IRCTL_DEVICES-1);
> +		       "0 and %d!\n", __func__, minor, MAX_IRCTL_DEVICES - 1);
>  		return -EBADRQC;
>  	}
>  
> @@ -380,7 +391,7 @@ int lirc_unregister_driver(int minor)
>  		return -ENOENT;
>  	}
>  
> -	cdev = &cdevs[minor];
> +	cdev = ir->cdev;
>  
>  	mutex_lock(&lirc_dev_lock);
>  
> @@ -410,6 +421,7 @@ int lirc_unregister_driver(int minor)
>  	} else {
>  		lirc_irctl_cleanup(ir);
>  		cdev_del(cdev);
> +		kfree(cdev);
>  		kfree(ir);
>  		irctls[minor] = NULL;
>  	}
> @@ -453,7 +465,7 @@ int lirc_dev_fop_open(struct inode *inode, struct file *file)
>  		goto error;
>  	}
>  
> -	cdev = &cdevs[iminor(inode)];
> +	cdev = ir->cdev;
>  	if (try_module_get(cdev->owner)) {
>  		ir->open++;
>  		retval = ir->d.set_use_inc(ir->d.data);
> @@ -484,13 +496,15 @@ EXPORT_SYMBOL(lirc_dev_fop_open);
>  int lirc_dev_fop_close(struct inode *inode, struct file *file)
>  {
>  	struct irctl *ir = irctls[iminor(inode)];
> -	struct cdev *cdev = &cdevs[iminor(inode)];
> +	struct cdev *cdev;
>  
>  	if (!ir) {
>  		printk(KERN_ERR "%s: called with invalid irctl\n", __func__);
>  		return -EINVAL;
>  	}
>  
> +	cdev = ir->cdev;
> +
>  	dev_dbg(ir->d.dev, LOGHEAD "close called\n", ir->d.name, ir->d.minor);
>  
>  	WARN_ON(mutex_lock_killable(&lirc_dev_lock));
> @@ -503,6 +517,7 @@ int lirc_dev_fop_close(struct inode *inode, struct file *file)
>  		lirc_irctl_cleanup(ir);
>  		cdev_del(cdev);
>  		irctls[ir->d.minor] = NULL;
> +		kfree(cdev);
>  		kfree(ir);
>  	}
>  
> diff --git a/include/media/lirc_dev.h b/include/media/lirc_dev.h
> index 630e702..168dd0b 100644
> --- a/include/media/lirc_dev.h
> +++ b/include/media/lirc_dev.h
> @@ -9,7 +9,7 @@
>  #ifndef _LINUX_LIRC_DEV_H
>  #define _LINUX_LIRC_DEV_H
>  
> -#define MAX_IRCTL_DEVICES 4
> +#define MAX_IRCTL_DEVICES 8
>  #define BUFLEN            16
>  
>  #define mod(n, div) ((n) % (div))