Commit 70d18804 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
Browse files

serdev: make synchronous write helper interruptible 



Allow the synchronous serdev_device_write() helper to be interrupted.

This is useful for cases where I/O is performed on behalf of user space
and we don't want to block indefinitely when using flow control.

Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0bbf0a88

drivers/tty/serdev/core.c

+14 −6
Original line number Diff line number Diff line
@@ -231,7 +231,7 @@ EXPORT_SYMBOL_GPL(serdev_device_write_buf); 


int serdev_device_write(struct serdev_device *serdev,

			const unsigned char *buf, size_t count,

			unsigned long timeout)

			long timeout)

{

	struct serdev_controller *ctrl = serdev->ctrl;

	int written = 0;
@@ -254,16 +254,24 @@ int serdev_device_write(struct serdev_device *serdev, 
		written += ret;

		buf += ret;

		count -= ret;

	} while (count &&

		 (timeout = wait_for_completion_timeout(&serdev->write_comp,

							timeout)));



		if (count == 0)

			break;



		timeout = wait_for_completion_interruptible_timeout(&serdev->write_comp,

								    timeout);

	} while (timeout > 0);

	mutex_unlock(&serdev->write_lock);



	if (ret < 0)

		return ret;



	if (timeout == 0 && written == 0)

	if (timeout <= 0 && written == 0) {

		if (timeout == -ERESTARTSYS)

			return -ERESTARTSYS;

		else

			return -ETIMEDOUT;

	}



	return written;

}

include/linux/serdev.h

+1 −1
Original line number Diff line number Diff line
@@ -210,7 +210,7 @@ void serdev_device_wait_until_sent(struct serdev_device *, long); 
int serdev_device_get_tiocm(struct serdev_device *);

int serdev_device_set_tiocm(struct serdev_device *, int, int);

void serdev_device_write_wakeup(struct serdev_device *);

int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, unsigned long);

int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long);

void serdev_device_write_flush(struct serdev_device *);

int serdev_device_write_room(struct serdev_device *);

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