usb: usbtmc: Add ioctl USBTMC488_IOCTL_WAIT_SRQ
PATCH 7/12 usb: usbtmc: Add ioctl USBTMC488_IOCTL_WAIT_SRQ
Am Donnerstag, den 17.05.2018, 19:03 +0200 schrieb Guido Kiener:
Quoted 10 lines
(quoted diff) +10
-0+static int usbtmc488_ioctl_wait_srq(struct usbtmc_file_data *file_data, + unsigned int __user *arg) +{ + struct usbtmc_device_data *data = file_data->data; + struct device *dev = &data->intf->dev; + int rv; + unsigned int timeout; + unsigned long expire; + + if (!data->iin_ep_present) {
Review
Quoted 10 lines
(quoted diff) +10
-0+ 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);
There is such a thing as threads sharing file descriptors. That leads to the question what happens to the mutex if this ioctl() is called multiple times.
Regards
Oliver
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