From 10f9e033c1e0e8563699b5839a2ff7f565dd72b2 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Fri, 3 Nov 2017 15:30:54 +0100 Subject: [PATCH] serdev: document driver callbacks Amend the driver-callback kerneldoc with calling context and expected return values. Note that this is based on the requirements and characteristics of the tty-port controller implementation which receives data in workqueue context and whose write_wakeup callback must not sleep. Also note that while the receive_buf callback returns an integer, the returned value is still expected to be non-negative (and no greater than the buffer-size argument). Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- include/linux/serdev.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/include/linux/serdev.h b/include/linux/serdev.h index 9929063..d7a9713 100644 --- a/include/linux/serdev.h +++ b/include/linux/serdev.h @@ -27,8 +27,10 @@ struct serdev_device; /** * struct serdev_device_ops - Callback operations for a serdev device - * @receive_buf: Function called with data received from device. - * @write_wakeup: Function called when ready to transmit more data. + * @receive_buf: Function called with data received from device; + * returns number of bytes accepted; may sleep. + * @write_wakeup: Function called when ready to transmit more data; must + * not sleep. */ struct serdev_device_ops { int (*receive_buf)(struct serdev_device *, const unsigned char *, size_t); -- 2.7.4