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-rw-r--r--drivers/usb/class/usbtmc.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index e4c80b44b55a..e177bac777f4 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -130,6 +130,7 @@ struct usbtmc_file_data {
u32 timeout;
u8 srq_byte;
atomic_t srq_asserted;
+ atomic_t closing;
u8 eom_val;
u8 term_char;
@@ -193,6 +194,8 @@ static int usbtmc_open(struct inode *inode, struct file *filp)
mutex_lock(&data->io_mutex);
file_data->data = data;
+ atomic_set(&file_data->closing, 0);
+
/* copy default values from device settings */
file_data->timeout = USBTMC_TIMEOUT;
file_data->term_char = data->TermChar;
@@ -223,6 +226,7 @@ static int usbtmc_flush(struct file *file, fl_owner_t id)
if (file_data == NULL)
return -ENODEV;
+ atomic_set(&file_data->closing, 1);
data = file_data->data;
/* wait for io to stop */
@@ -576,6 +580,54 @@ static int usbtmc488_ioctl_read_stb(struct usbtmc_file_data *file_data,
return rv;
}
+static int usbtmc488_ioctl_wait_srq(struct usbtmc_file_data *file_data,
+ __u32 __user *arg)
+{
+ struct usbtmc_device_data *data = file_data->data;
+ struct device *dev = &data->intf->dev;
+ int rv;
+ u32 timeout;
+ unsigned long expire;
+
+ if (!data->iin_ep_present) {
+ dev_dbg(dev, "no interrupt endpoint present\n");
+ return -EFAULT;
+ }
+
+ if (get_user(timeout, arg))
+ return -EFAULT;
+
+ expire = msecs_to_jiffies(timeout);
+
+ mutex_unlock(&data->io_mutex);
+
+ rv = wait_event_interruptible_timeout(
+ data->waitq,
+ atomic_read(&file_data->srq_asserted) != 0 ||
+ atomic_read(&file_data->closing),
+ expire);
+
+ mutex_lock(&data->io_mutex);
+
+ /* Note! disconnect or close could be called in the meantime */
+ if (atomic_read(&file_data->closing) || data->zombie)
+ rv = -ENODEV;
+
+ if (rv < 0) {
+ /* dev can be invalid now! */
+ pr_debug("%s - wait interrupted %d\n", __func__, rv);
+ return rv;
+ }
+
+ if (rv == 0) {
+ dev_dbg(dev, "%s - wait timed out\n", __func__);
+ return -ETIMEDOUT;
+ }
+
+ dev_dbg(dev, "%s - srq asserted\n", __func__);
+ return 0;
+}
+
static int usbtmc488_ioctl_simple(struct usbtmc_device_data *data,
void __user *arg, unsigned int cmd)
{
@@ -2142,6 +2194,11 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
retval = usbtmc488_ioctl_trigger(file_data);
break;
+ case USBTMC488_IOCTL_WAIT_SRQ:
+ retval = usbtmc488_ioctl_wait_srq(file_data,
+ (__u32 __user *)arg);
+ break;
+
case USBTMC_IOCTL_CANCEL_IO:
retval = usbtmc_ioctl_cancel_io(file_data);
break;