From c757096ea1033c46ab768709847f7776b7e92a92 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Wed, 9 Oct 2019 06:41:08 +0200 Subject: can: rx-offload: add skb queue for use during ISR Adding a skb to the skb_queue in rx-offload requires to take a lock. This commit avoids this by adding an unlocked skb queue that is appended at the end of the ISR. Having one lock at the end of the ISR should be OK as the HW is empty, not about to overflow. Link: https://lore.kernel.org/r/20210724204745.736053-2-mkl@pengutronix.de Tested-by: Oleksij Rempel Co-developed-by: Kurt Van Dijck Signed-off-by: Kurt Van Dijck Signed-off-by: Marc Kleine-Budde --- include/linux/can/rx-offload.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/can') diff --git a/include/linux/can/rx-offload.h b/include/linux/can/rx-offload.h index 40882df7105e..d71c938e17d0 100644 --- a/include/linux/can/rx-offload.h +++ b/include/linux/can/rx-offload.h @@ -20,6 +20,7 @@ struct can_rx_offload { bool drop); struct sk_buff_head skb_queue; + struct sk_buff_head skb_irq_queue; u32 skb_queue_len_max; unsigned int mb_first; @@ -48,6 +49,7 @@ unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload, unsigned int *frame_len_ptr); int can_rx_offload_queue_tail(struct can_rx_offload *offload, struct sk_buff *skb); +void can_rx_offload_irq_finish(struct can_rx_offload *offload); void can_rx_offload_del(struct can_rx_offload *offload); void can_rx_offload_enable(struct can_rx_offload *offload); -- cgit v1.2.3 From 1e0d8e507ea42dd37f52636db300de7ea7118012 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Fri, 7 May 2021 17:58:30 +0200 Subject: can: rx-offload: can_rx_offload_irq_finish(): directly call napi_schedule() Instead of calling can_rx_offload_schedule() call napi_schedule() directly. As this was the last use of can_rx_offload_schedule() remove this helper function. Link: https://lore.kernel.org/r/20210724204745.736053-3-mkl@pengutronix.de Tested-by: Oleksij Rempel Signed-off-by: Marc Kleine-Budde --- include/linux/can/rx-offload.h | 5 ----- 1 file changed, 5 deletions(-) (limited to 'include/linux/can') diff --git a/include/linux/can/rx-offload.h b/include/linux/can/rx-offload.h index d71c938e17d0..516f64df0ebc 100644 --- a/include/linux/can/rx-offload.h +++ b/include/linux/can/rx-offload.h @@ -53,11 +53,6 @@ void can_rx_offload_irq_finish(struct can_rx_offload *offload); void can_rx_offload_del(struct can_rx_offload *offload); void can_rx_offload_enable(struct can_rx_offload *offload); -static inline void can_rx_offload_schedule(struct can_rx_offload *offload) -{ - napi_schedule(&offload->napi); -} - static inline void can_rx_offload_disable(struct can_rx_offload *offload) { napi_disable(&offload->napi); -- cgit v1.2.3 From 30bfec4fec5902731c8823f51c5332e6f2b2312a Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Mon, 10 May 2021 22:51:39 +0200 Subject: can: rx-offload: can_rx_offload_threaded_irq_finish(): add new function to be called from threaded interrupt MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit After reading all CAN frames from the controller in the IRQ handler and storing them into a skb_queue, the driver calls napi_schedule(). In the napi poll function the skb from the skb_queue are then pushed into the networking stack. However if napi_schedule() is called from a threaded IRQ handler this triggers the following error: | NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #08!!! To avoid this, create a new rx-offload function (can_rx_offload_threaded_irq_finish()) with a call to local_bh_disable()/local_bh_enable() around the napi_schedule() call. Convert all drivers that call can_rx_offload_irq_finish() from threaded IRQ context to can_rx_offload_threaded_irq_finish(). Link: https://lore.kernel.org/r/20210724204745.736053-4-mkl@pengutronix.de Suggested-by: Daniel Glöckner Tested-by: Oleksij Rempel Signed-off-by: Marc Kleine-Budde --- include/linux/can/rx-offload.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/can') diff --git a/include/linux/can/rx-offload.h b/include/linux/can/rx-offload.h index 516f64df0ebc..c11477620403 100644 --- a/include/linux/can/rx-offload.h +++ b/include/linux/can/rx-offload.h @@ -50,6 +50,7 @@ unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload, int can_rx_offload_queue_tail(struct can_rx_offload *offload, struct sk_buff *skb); void can_rx_offload_irq_finish(struct can_rx_offload *offload); +void can_rx_offload_threaded_irq_finish(struct can_rx_offload *offload); void can_rx_offload_del(struct can_rx_offload *offload); void can_rx_offload_enable(struct can_rx_offload *offload); -- cgit v1.2.3 From 8345a330738149389dc8883573c9264965922e08 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Wed, 16 Jun 2021 11:55:26 +0200 Subject: can: bittiming: fix documentation for struct can_tdc This patch fixes a typo in the documentation for struct can_tdc::tdcv. The number "0" refers to automatic mode not the letter "O". Further two grammar errors in the documentation for struct can_tdc are fixed. First grammar error: add a missing third person 's'. Second grammar error: replace "such as" by "such that". The intent is to give a condition, not an example. Fixes: 289ea9e4ae59 ("can: add new CAN FD bittiming parameters: Transmitter Delay Compensation (TDC)") Link: https://lore.kernel.org/r/20210616095922.2430415-1-mkl@pengutronix.de Link: https://lore.kernel.org/r/20210616124057.60723-1-mailhol.vincent@wanadoo.fr Co-developed-by: Vincent Mailhol Signed-off-by: Vincent Mailhol Acked-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde --- include/linux/can/bittiming.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/can') diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h index ae7a3411167c..9de6e9053e34 100644 --- a/include/linux/can/bittiming.h +++ b/include/linux/can/bittiming.h @@ -37,7 +37,7 @@ * 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 + * 0: automatic mode. The controller dynamically measures @tdcv * for each transmitted CAN FD frame. * * Other values: manual mode. Use the fixed provided value. @@ -45,7 +45,7 @@ * @tdco: Transmitter Delay Compensation Offset. Offset value, in time * quanta, defining the distance between the start of the bit * reception on the RX pin of the transceiver and the SSP - * position such as SSP = @tdcv + @tdco. + * position such that SSP = @tdcv + @tdco. * * If @tdco is zero, then TDC is disabled and both @tdcv and * @tdcf should be ignored. -- cgit v1.2.3 From 896e7f3e7424d6cc1436172740aa76ebb2c1b248 Mon Sep 17 00:00:00 2001 From: Angelo Dureghello Date: Fri, 2 Jul 2021 11:48:37 +0200 Subject: can: flexcan: add platform data header Add platform data header for flexcan. Link: https://lore.kernel.org/r/20210702094841.327679-1-angelo@kernel-space.org Signed-off-by: Angelo Dureghello Signed-off-by: Marc Kleine-Budde --- include/linux/can/platform/flexcan.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 include/linux/can/platform/flexcan.h (limited to 'include/linux/can') diff --git a/include/linux/can/platform/flexcan.h b/include/linux/can/platform/flexcan.h new file mode 100644 index 000000000000..1b536fb999de --- /dev/null +++ b/include/linux/can/platform/flexcan.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2021 Angelo Dureghello + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _CAN_PLATFORM_FLEXCAN_H +#define _CAN_PLATFORM_FLEXCAN_H + +struct flexcan_platform_data { + u32 clock_frequency; + u8 clk_src; +}; + +#endif /* _CAN_PLATFORM_FLEXCAN_H */ -- cgit v1.2.3 From 6e86a1543c378f2e8837ad88f361b7bf606c80f7 Mon Sep 17 00:00:00 2001 From: Oleksij Rempel Date: Wed, 18 Aug 2021 09:12:32 +0200 Subject: can: dev: provide optional GPIO based termination support For CAN buses to work, a termination resistor has to be present at both ends of the bus. This resistor is usually 120 Ohms, other values may be required for special bus topologies. This patch adds support for a generic GPIO based CAN termination. The resistor value has to be specified via device tree, and it can only be attached to or detached from the bus. By default the termination is not active. Link: https://lore.kernel.org/r/20210818071232.20585-4-o.rempel@pengutronix.de Signed-off-by: Oleksij Rempel Signed-off-by: Marc Kleine-Budde --- include/linux/can/dev.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/can') diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index 27b275e463da..2413253e54c7 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -32,6 +32,12 @@ enum can_mode { CAN_MODE_SLEEP }; +enum can_termination_gpio { + CAN_TERMINATION_GPIO_DISABLED = 0, + CAN_TERMINATION_GPIO_ENABLED, + CAN_TERMINATION_GPIO_MAX, +}; + /* * CAN common private data */ @@ -55,6 +61,8 @@ struct can_priv { unsigned int termination_const_cnt; const u16 *termination_const; u16 termination; + struct gpio_desc *termination_gpio; + u16 termination_gpio_ohms[CAN_TERMINATION_GPIO_MAX]; enum can_state state; -- cgit v1.2.3