Merge branch 'fixes-rc1' into fixes

3 files changed, 96 insertions, 8 deletions

diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h
index 707575c668f4..ae7a3411167c 100644
--- 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@pengutronix.de>
+ * Copyright (c) 2021 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
  */
 
 #ifndef _CAN_BITTIMING_H
@@ -10,9 +11,83 @@
 
 #define CAN_SYNC_SEG 1
 
+
+/* Kilobits and Megabits per second */
+#define CAN_KBPS 1000UL
+#define CAN_MBPS 1000000UL
+
+/* Megahertz */
+#define CAN_MHZ 1000000UL
+
+/*
+ * 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 transmitted CAN FD frame.
+ *
+ *	  Other values: manual mode. Use the fixed provided value.
+ *
+ * @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.
+ *
+ *	If @tdco is zero, then TDC is disabled and both @tdcv and
+ *	@tdcf should be ignored.
+ *
+ * @tdcf: Transmitter Delay Compensation Filter window. Defines the
+ *	minimum value for the SSP position in time quanta. If SSP is
+ *	less than @tdcf, then no delay compensations occur and the
+ *	normal sampling point is used instead. The feature is enabled
+ *	if and only if @tdcv is set to zero (automatic mode) and @tdcf
+ *	is configured to a value greater than @tdco.
+ */
+struct can_tdc {
+	u32 tdcv;
+	u32 tdco;
+	u32 tdcf;
+};
+
+/*
+ * struct can_tdc_const - CAN hardware-dependent constant for
+ *	Transmission Delay Compensation
+ *
+ * @tdcv_max: Transmitter Delay Compensation Value maximum value.
+ *	Should be set to zero if the controller does not support
+ *	manual mode for tdcv.
+ * @tdco_max: Transmitter Delay Compensation Offset maximum value.
+ *	Should not be zero. If the controller does not support TDC,
+ *	then the pointer to this structure should be NULL.
+ * @tdcf_max: Transmitter Delay Compensation Filter window maximum
+ *	value. Should be set to zero if the controller does not
+ *	support this feature.
+ */
+struct can_tdc_const {
+	u32 tdcv_max;
+	u32 tdco_max;
+	u32 tdcf_max;
+};
+
 #ifdef CONFIG_CAN_CALC_BITTIMING
 int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 		       const struct can_bittiming_const *btc);
+
+void can_calc_tdco(struct net_device *dev);
 #else /* !CONFIG_CAN_CALC_BITTIMING */
 static inline int
 can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
@@ -21,6 +96,10 @@ can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 	netdev_err(dev, "bit-timing calculation not available\n");
 	return -EINVAL;
 }
+
+static inline void can_calc_tdco(struct net_device *dev)
+{
+}
 #endif /* CONFIG_CAN_CALC_BITTIMING */
 
 int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index ac4d83a1ab81..27b275e463da 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -39,19 +39,23 @@ struct can_priv {
 	struct net_device *dev;
 	struct can_device_stats can_stats;
 
-	struct can_bittiming bittiming, data_bittiming;
 	const struct can_bittiming_const *bittiming_const,
 		*data_bittiming_const;
-	const u16 *termination_const;
-	unsigned int termination_const_cnt;
-	u16 termination;
-	const u32 *bitrate_const;
+	struct can_bittiming bittiming, data_bittiming;
+	const struct can_tdc_const *tdc_const;
+	struct can_tdc tdc;
+
 	unsigned int bitrate_const_cnt;
+	const u32 *bitrate_const;
 	const u32 *data_bitrate_const;
 	unsigned int data_bitrate_const_cnt;
 	u32 bitrate_max;
 	struct can_clock clock;
 
+	unsigned int termination_const_cnt;
+	const u16 *termination_const;
+	u16 termination;
+
 	enum can_state state;
 
 	/* CAN controller features - see include/uapi/linux/can/netlink.h */
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index 685f34cfba20..d311bc369a39 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -23,7 +23,8 @@ struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
 				   u8 *len_ptr, unsigned int *frame_len_ptr);
 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx,
 			      unsigned int *frame_len_ptr);
-void can_free_echo_skb(struct net_device *dev, unsigned int idx);
+void can_free_echo_skb(struct net_device *dev, unsigned int idx,
+		       unsigned int *frame_len_ptr);
 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 				struct canfd_frame **cfd);
@@ -65,8 +66,12 @@ static inline void can_skb_reserve(struct sk_buff *skb)
 
 static inline void can_skb_set_owner(struct sk_buff *skb, struct sock *sk)
 {
-	if (sk) {
-		sock_hold(sk);
+	/* If the socket has already been closed by user space, the
+	 * refcount may already be 0 (and the socket will be freed
+	 * after the last TX skb has been freed). So only increase
+	 * socket refcount if the refcount is > 0.
+	 */
+	if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
 		skb->destructor = sock_efree;
 		skb->sk = sk;
 	}