From: Bongsu Jeon bongsu.jeon@samsung.com
In previous version, the user level virtual device application that used this driver should have the polling scheme to read a NCI frame. To remove this polling scheme, use Wait Queue.
Signed-off-by: Bongsu Jeon bongsu.jeon@samsung.com --- drivers/nfc/virtual_ncidev.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/nfc/virtual_ncidev.c b/drivers/nfc/virtual_ncidev.c index 2ee0ec4bb739..221fa3bb8705 100644 --- a/drivers/nfc/virtual_ncidev.c +++ b/drivers/nfc/virtual_ncidev.c @@ -10,6 +10,7 @@ #include <linux/module.h> #include <linux/miscdevice.h> #include <linux/mutex.h> +#include <linux/wait.h> #include <net/nfc/nci_core.h>
enum virtual_ncidev_mode { @@ -27,6 +28,7 @@ enum virtual_ncidev_mode { NFC_PROTO_ISO15693_MASK)
static enum virtual_ncidev_mode state; +static DECLARE_WAIT_QUEUE_HEAD(wq); static struct miscdevice miscdev; static struct sk_buff *send_buff; static struct nci_dev *ndev; @@ -61,6 +63,7 @@ static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb) } send_buff = skb_copy(skb, GFP_KERNEL); mutex_unlock(&nci_mutex); + wake_up_interruptible(&wq);
return 0; } @@ -77,9 +80,11 @@ static ssize_t virtual_ncidev_read(struct file *file, char __user *buf, size_t actual_len;
mutex_lock(&nci_mutex); - if (!send_buff) { + while (!send_buff) { mutex_unlock(&nci_mutex); - return 0; + if (wait_event_interruptible(wq, send_buff)) + return -EFAULT; + mutex_lock(&nci_mutex); }
actual_len = min_t(size_t, count, send_buff->len);