On 2021-02-24 08:31, Marc Kleine-Budde wrote:
On 24.02.2021 09:20:04, Vincent Mailhol wrote:
--- a/include/linux/can/bittiming.h
+++ b/include/linux/can/bittiming.h
@@ -1,5 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (c) 2020 Pengutronix, Marc Kleine-Budde <kernel@xxxxxxxxxxxxxx>
+ * Copyright (c) 2021 Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
*/
#ifndef _CAN_BITTIMING_H
@@ -10,6 +11,70 @@
#define CAN_SYNC_SEG 1
+/*
+ * struct can_tdc - CAN FD Transmission Delay Compensation parameters
+ *
+ * At high bit rates, the propagation delay from the TX pin to the RX
+ * pin of the transceiver causes measurement errors: the sample point
+ * on the RX pin might occur on the previous bit.
+ *
+ * To solve this issue, ISO 11898-1 introduces in section 11.3.3
+ * "Transmitter delay compensation" a SSP (Secondary Sample Point)
+ * equal to the distance, in time quanta, from the start of the bit
+ * time on the TX pin to the actual measurement on the RX pin.
+ *
+ * This structure contains the parameters to calculate that SSP.
+ *
+ * @tdcv: Transmitter Delay Compensation Value. Distance, in time
+ * quanta, from when the bit is sent on the TX pin to when it is
+ * received on the RX pin of the transmitter. Possible options:
+ *
+ * O: automatic mode. The controller dynamically measure @tdcv
+ * for each transmited CAN FD frame.
^^^
transmitted
Fixed while applying to linux-can-next/testing. As net-next ist still
closed, there is still some time to the next pull request and I'll
squash patches if needed.
Hi Marc,
Can't find this in linux-can-next/testing
https://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git/log/?h=testing
Regards,
jimmy
