diff options
Diffstat (limited to 'drivers/misc/ibmasm/ibmasmfs.c')
| -rw-r--r-- | drivers/misc/ibmasm/ibmasmfs.c | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/drivers/misc/ibmasm/ibmasmfs.c b/drivers/misc/ibmasm/ibmasmfs.c index 866e867e68f2..c87ef7d82b70 100644 --- a/drivers/misc/ibmasm/ibmasmfs.c +++ b/drivers/misc/ibmasm/ibmasmfs.c @@ -374,6 +374,7 @@ static int event_file_open(struct inode *inode, struct file *file) ibmasm_event_reader_register(sp, &event_data->reader); event_data->sp = sp; + event_data->active = 0; file->private_data = event_data; return 0; } @@ -391,7 +392,9 @@ static ssize_t event_file_read(struct file *file, char __user *buf, size_t count { struct ibmasmfs_event_data *event_data = file->private_data; struct event_reader *reader = &event_data->reader; + struct service_processor *sp = event_data->sp; int ret; + unsigned long flags; if (*offset < 0) return -EINVAL; @@ -400,17 +403,32 @@ static ssize_t event_file_read(struct file *file, char __user *buf, size_t count if (*offset != 0) return 0; - ret = ibmasm_get_next_event(event_data->sp, reader); + spin_lock_irqsave(&sp->lock, flags); + if (event_data->active) { + spin_unlock_irqrestore(&sp->lock, flags); + return -EBUSY; + } + event_data->active = 1; + spin_unlock_irqrestore(&sp->lock, flags); + + ret = ibmasm_get_next_event(sp, reader); if (ret <= 0) - return ret; + goto out; - if (count < reader->data_size) - return -EINVAL; + if (count < reader->data_size) { + ret = -EINVAL; + goto out; + } - if (copy_to_user(buf, reader->data, reader->data_size)) - return -EFAULT; + if (copy_to_user(buf, reader->data, reader->data_size)) { + ret = -EFAULT; + goto out; + } + ret = reader->data_size; - return reader->data_size; +out: + event_data->active = 0; + return ret; } static ssize_t event_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset) @@ -424,7 +442,7 @@ static ssize_t event_file_write(struct file *file, const char __user *buf, size_ if (*offset != 0) return 0; - wake_up_interruptible(&event_data->reader.wait); + ibmasm_cancel_next_event(&event_data->reader); return 0; } |