ioctl USBTMC_IOCTL_CANCEL_IO stops and kills all flying urbs of
last USBTMC_IOCTL_READ and USBTMC_IOCTL_WRITE function calls.
A subsequent call to USBTMC_IOCTL_READ or
USBTMC_IOCTL_WRITE_RESULT returns -ECANCELED with
information about current transferred data.
Signed-off-by: Guido Kiener <guido.kiener@xxxxxxxxxxxxxxxxx>
Reviewed-by: Steve Bayless <steve_bayless@xxxxxxxxxxxx>
---
drivers/usb/class/usbtmc.c | 4 ++++
include/uapi/linux/usb/tmc.h | 3 +++
2 files changed, 7 insertions(+)
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 32b588eb0304..67cdf5df90d7 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -2141,6 +2141,10 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case USBTMC488_IOCTL_TRIGGER:
retval = usbtmc488_ioctl_trigger(file_data);
break;
+
+ case USBTMC_IOCTL_CANCEL_IO:
+ retval = usbtmc_ioctl_cancel_io(file_data);
+ break;
}
skip_io_on_zombie:
diff --git a/include/uapi/linux/usb/tmc.h b/include/uapi/linux/usb/tmc.h
index c75354dfd592..934991624a28 100644
--- a/include/uapi/linux/usb/tmc.h
+++ b/include/uapi/linux/usb/tmc.h
@@ -97,6 +97,9 @@ struct usbtmc_message {
#define USBTMC488_IOCTL_LOCAL_LOCKOUT _IO(USBTMC_IOC_NR, 21)
#define USBTMC488_IOCTL_TRIGGER _IO(USBTMC_IOC_NR, 22)
+/* Cancel and cleanup asynchronous calls */
+#define USBTMC_IOCTL_CANCEL_IO _IO(USBTMC_IOC_NR, 35)
+
/* Driver encoded usb488 capabilities */
#define USBTMC488_CAPABILITY_TRIGGER 1
#define USBTMC488_CAPABILITY_SIMPLE 2
--
2.17.1
--
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