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Commit b3b0abe1 authored by Clemens Ladisch's avatar Clemens Ladisch Committed by Jaroslav Kysela
Browse files

[ALSA] return ENODEV for disconnected devices 



Modules: ALSA Core

Add dummy functions that return -ENODEV for the struct file_operations
of a disconnected device.  Without such functions, userspace would get
ENOTTY.

Signed-off-by: default avatarClemens Ladisch <clemens@ladisch.de>
parent 0b7bed4e

sound/core/init.c

+42 −0
Original line number Diff line number Diff line
@@ -169,11 +169,44 @@ struct snd_card *snd_card_new(int idx, const char *xid, 
      	return NULL;

}



static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)

{

	return -ENODEV;

}



static ssize_t snd_disconnect_read(struct file *file, char __user *buf,

				   size_t count, loff_t *offset)

{

	return -ENODEV;

}



static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,

				    size_t count, loff_t *offset)

{

	return -ENODEV;

}



static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)

{

	return POLLERR | POLLNVAL;

}



static long snd_disconnect_ioctl(struct file *file,

				 unsigned int cmd, unsigned long arg)

{

	return -ENODEV;

}



static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)

{

	return -ENODEV;

}



static int snd_disconnect_fasync(int fd, struct file *file, int on)

{

	return -ENODEV;

}



/**

 *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)

 *  @card: soundcard structure
@@ -224,7 +257,16 @@ int snd_card_disconnect(struct snd_card *card) 
		memset(f_ops, 0, sizeof(*f_ops));

		f_ops->owner = file->f_op->owner;

		f_ops->release = file->f_op->release;

		f_ops->llseek = snd_disconnect_llseek;

		f_ops->read = snd_disconnect_read;

		f_ops->write = snd_disconnect_write;

		f_ops->poll = snd_disconnect_poll;

		f_ops->unlocked_ioctl = snd_disconnect_ioctl;

#ifdef CONFIG_COMPAT

		f_ops->compat_ioctl = snd_disconnect_ioctl;

#endif

		f_ops->mmap = snd_disconnect_mmap;

		f_ops->fasync = snd_disconnect_fasync;



		s_f_ops->next = card->s_f_ops;

		card->s_f_ops = s_f_ops;