Commit 444fb98e authored by Thierry Escande's avatar Thierry Escande Committed by Samuel Ortiz
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NFC: digital: Add a note about asynchronous functions 



This explains how and why the timeout parameter must be handled by the
driver implementation.

Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent ea87a5ef

include/net/nfc/digital.h

+10 −0
Original line number Diff line number Diff line
@@ -122,6 +122,16 @@ typedef void (*nfc_digital_cmd_complete_t)(struct nfc_digital_dev *ddev, 
 *	switch_rf to turn the radio on. A call to in|tg_configure_hw must turn

 *	the device radio on.

 * @abort_cmd: Discard the last sent command.

 *

 * Notes: Asynchronous functions have a timeout parameter. It is the driver

 *	responsibility to call the digital stack back through the

 *	nfc_digital_cmd_complete_t callback when no RF respsonse has been

 *	received within the specified time (in milliseconds). In that case the

 *	driver must set the resp sk_buff to ERR_PTR(-ETIMEDOUT).

 *	Since the digital stack serializes commands to be sent, it's mandatory

 *	for the driver to handle the timeout correctly. Otherwise the stack

 *	would not be able to send new commands, waiting for the reply of the

 *	current one.

 */

struct nfc_digital_ops {

	int (*in_configure_hw)(struct nfc_digital_dev *ddev, int type,