| Message ID | 20210814101728.75334-5-mailhol.vincent@wanadoo.fr |
|---|---|
| State | New |
| Headers | show |
| Series | iplink_can: cleaning, fixes and adding TDC support. | expand |
On 14.08.2021 19:17:28, Vincent Mailhol wrote: > 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. > > This issue is addressed in ISO 11898-1 section 11.3.3 "Transmitter > delay compensation" (TDC). > > This patch brings command line support to nine TDC parameters which > were recently added to the kernel's CAN netlink interface in order to > implement TDC: > - IFLA_CAN_TDC_TDCV_MIN: Transmitter Delay Compensation Value > minimum value > - IFLA_CAN_TDC_TDCV_MAX: Transmitter Delay Compensation Value > maximum value > - IFLA_CAN_TDC_TDCO_MIN: Transmitter Delay Compensation Offset > minimum value > - IFLA_CAN_TDC_TDCO_MAX: Transmitter Delay Compensation Offset > maximum value > - IFLA_CAN_TDC_TDCF_MIN: Transmitter Delay Compensation Filter > window minimum value > - IFLA_CAN_TDC_TDCF_MAX: Transmitter Delay Compensation Filter > window maximum value > - IFLA_CAN_TDC_TDCV: Transmitter Delay Compensation Value > - IFLA_CAN_TDC_TDCO: Transmitter Delay Compensation Offset > - IFLA_CAN_TDC_TDCF: Transmitter Delay Compensation Filter window > > All those new parameters are nested together into the attribute > IFLA_CAN_TDC. > > A tdc-mode parameter allow to specify how to operate. Valid options > are: > > * auto: the transmitter automatically measures TDCV. As such, TDCV > values can not be manually provided. In this mode, the user must > specify TDCO and may also specify TDCF if supported. > > * manual: Use the TDCV value provided by the user are used. In this ^^^^^ ^^^ singular plural > mode, the user must specify both TDCV and TDCO and may also > specify TDCF if supported. > Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
On Mon. 16 août 2021 at 17:12, Marc Kleine-Budde <mkl@pengutronix.de> wrote: > On 14.08.2021 19:17:28, Vincent Mailhol wrote: > > 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. > > > > This issue is addressed in ISO 11898-1 section 11.3.3 "Transmitter > > delay compensation" (TDC). > > > > This patch brings command line support to nine TDC parameters which > > were recently added to the kernel's CAN netlink interface in order to > > implement TDC: > > - IFLA_CAN_TDC_TDCV_MIN: Transmitter Delay Compensation Value > > minimum value > > - IFLA_CAN_TDC_TDCV_MAX: Transmitter Delay Compensation Value > > maximum value > > - IFLA_CAN_TDC_TDCO_MIN: Transmitter Delay Compensation Offset > > minimum value > > - IFLA_CAN_TDC_TDCO_MAX: Transmitter Delay Compensation Offset > > maximum value > > - IFLA_CAN_TDC_TDCF_MIN: Transmitter Delay Compensation Filter > > window minimum value > > - IFLA_CAN_TDC_TDCF_MAX: Transmitter Delay Compensation Filter > > window maximum value > > - IFLA_CAN_TDC_TDCV: Transmitter Delay Compensation Value > > - IFLA_CAN_TDC_TDCO: Transmitter Delay Compensation Offset > > - IFLA_CAN_TDC_TDCF: Transmitter Delay Compensation Filter window > > > > All those new parameters are nested together into the attribute > > IFLA_CAN_TDC. > > > > A tdc-mode parameter allow to specify how to operate. Valid options > > are: > > > > * auto: the transmitter automatically measures TDCV. As such, TDCV > > values can not be manually provided. In this mode, the user must > > specify TDCO and may also specify TDCF if supported. > > > > * manual: Use the TDCV value provided by the user are used. In this > ^^^^^ ^^^ > singular plural ACK. I fixed that broken grammar in my local branch. As commented before, I will send the next version of the iproute series after we agree on the kernel part (unless someone finds a major issue). FYI, this is the fixed sentence: * manual: use a static TDCV provided by the user. In this mode, the user must specify both TDCV and TDCO and may also specify TDCF if supported. Yours sincerely, Vincent
I originally sent the below answer on Saturday but omitted to CC the mailing list so only Marc received it. Resending it for the record. On Sat. 14 Aug 2021 at 20:14, Marc Kleine-Budde <mkl@pengutronix.de> wrote: > On 14.08.2021 19:17:28, Vincent Mailhol wrote: > > include/uapi/linux/can/netlink.h | 30 +++++++- > > IIRC, changes of the uapi headers will be pull in regularly from the > mainline kernel. I see... This kind of makes sense. However, that would be less easier to test as people will have to update the uapi headers by hand. For now, I will just wait and I will send a new version without the uapi header once we agree on the kernel part. Yours sincerely, Vincent
On 14.08.2021 19:17:28, Vincent Mailhol wrote: > 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. > > This issue is addressed in ISO 11898-1 section 11.3.3 "Transmitter > delay compensation" (TDC). > > This patch brings command line support to nine TDC parameters which > were recently added to the kernel's CAN netlink interface in order to > implement TDC: > - IFLA_CAN_TDC_TDCV_MIN: Transmitter Delay Compensation Value > minimum value > - IFLA_CAN_TDC_TDCV_MAX: Transmitter Delay Compensation Value > maximum value > - IFLA_CAN_TDC_TDCO_MIN: Transmitter Delay Compensation Offset > minimum value > - IFLA_CAN_TDC_TDCO_MAX: Transmitter Delay Compensation Offset > maximum value > - IFLA_CAN_TDC_TDCF_MIN: Transmitter Delay Compensation Filter > window minimum value > - IFLA_CAN_TDC_TDCF_MAX: Transmitter Delay Compensation Filter > window maximum value > - IFLA_CAN_TDC_TDCV: Transmitter Delay Compensation Value > - IFLA_CAN_TDC_TDCO: Transmitter Delay Compensation Offset > - IFLA_CAN_TDC_TDCF: Transmitter Delay Compensation Filter window > > All those new parameters are nested together into the attribute > IFLA_CAN_TDC. > > A tdc-mode parameter allow to specify how to operate. Valid options > are: > > * auto: the transmitter automatically measures TDCV. As such, TDCV > values can not be manually provided. In this mode, the user must > specify TDCO and may also specify TDCF if supported. > > * manual: Use the TDCV value provided by the user are used. In this > mode, the user must specify both TDCV and TDCO and may also > specify TDCF if supported. > > * off: TDC is explicitly disabled. > > * tdc-mode parameter omitted (default mode): the kernel decides > whether TDC should be enabled or not and if so, it calculates the > TDC values. TDC parameters are an expert option and the average > user is not expected to provide those, thus the presence of this > "default mode". > > TDCV is always reported in manual mode. In auto mode, TDCV is reported > only if the value is available. Especially, the TDCV might not be > available if the controller has no feature to report it or if the > value in not yet available (i.e. no data sent yet and measurement did > not occur). > > TDCF is reported only if tdcf_max is not zero (i.e. if supported by the controller). > > For reference, here are a few samples of how the output looks like: > > $ ip link set can0 type can bitrate 1000000 dbitrate 8000000 fd on tdco 7 tdcf 8 tdc-mode auto > > $ ip --details link show can0 > 1: can0: <NOARP,ECHO> mtu 72 qdisc noop state DOWN mode DEFAULT group default qlen 10 > link/can promiscuity 0 minmtu 0 maxmtu 0 > can <FD,TDC_AUTO> state STOPPED (berr-counter tx 0 rx 0) restart-ms 0 ^^^^^^^^ This is just the supported mode(s), right? > bitrate 1000000 sample-point 0.750 > tq 12 prop-seg 29 phase-seg1 30 phase-seg2 20 sjw 1 brp 1 > ES582.1/ES584.1: tseg1 2..256 tseg2 2..128 sjw 1..128 brp 1..512 brp_inc 1 > dbitrate 8000000 dsample-point 0.700 > dtq 12 dprop-seg 3 dphase-seg1 3 dphase-seg2 3 dsjw 1 dbrp 1 > tdco 7 tdcf 8 > ES582.1/ES584.1: dtseg1 2..32 dtseg2 1..16 dsjw 1..8 dbrp 1..32 dbrp_inc 1 > tdco 0..127 tdcf 0..127 > clock 80000000 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 Is there a way to figure out, which tdc mode is currently active? AFAICS just implicitly: - tdco + tdcv -> manual - tdco -> automatic - neither -> off correct? regards, Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
On Mon. 16 Aug. 2021 at 22:51, Marc Kleine-Budde <mkl@pengutronix.de> wrote: > On 14.08.2021 19:17:28, Vincent Mailhol wrote: > > 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. > > > > This issue is addressed in ISO 11898-1 section 11.3.3 "Transmitter > > delay compensation" (TDC). > > > > This patch brings command line support to nine TDC parameters which > > were recently added to the kernel's CAN netlink interface in order to > > implement TDC: > > - IFLA_CAN_TDC_TDCV_MIN: Transmitter Delay Compensation Value > > minimum value > > - IFLA_CAN_TDC_TDCV_MAX: Transmitter Delay Compensation Value > > maximum value > > - IFLA_CAN_TDC_TDCO_MIN: Transmitter Delay Compensation Offset > > minimum value > > - IFLA_CAN_TDC_TDCO_MAX: Transmitter Delay Compensation Offset > > maximum value > > - IFLA_CAN_TDC_TDCF_MIN: Transmitter Delay Compensation Filter > > window minimum value > > - IFLA_CAN_TDC_TDCF_MAX: Transmitter Delay Compensation Filter > > window maximum value > > - IFLA_CAN_TDC_TDCV: Transmitter Delay Compensation Value > > - IFLA_CAN_TDC_TDCO: Transmitter Delay Compensation Offset > > - IFLA_CAN_TDC_TDCF: Transmitter Delay Compensation Filter window > > > > All those new parameters are nested together into the attribute > > IFLA_CAN_TDC. > > > > A tdc-mode parameter allow to specify how to operate. Valid options > > are: > > > > * auto: the transmitter automatically measures TDCV. As such, TDCV > > values can not be manually provided. In this mode, the user must > > specify TDCO and may also specify TDCF if supported. > > > > * manual: Use the TDCV value provided by the user are used. In this > > mode, the user must specify both TDCV and TDCO and may also > > specify TDCF if supported. > > > > * off: TDC is explicitly disabled. > > > > * tdc-mode parameter omitted (default mode): the kernel decides > > whether TDC should be enabled or not and if so, it calculates the > > TDC values. TDC parameters are an expert option and the average > > user is not expected to provide those, thus the presence of this > > "default mode". > > > > TDCV is always reported in manual mode. In auto mode, TDCV is reported > > only if the value is available. Especially, the TDCV might not be > > available if the controller has no feature to report it or if the > > value in not yet available (i.e. no data sent yet and measurement did > > not occur). > > > > TDCF is reported only if tdcf_max is not zero (i.e. if supported by the controller). > > > > For reference, here are a few samples of how the output looks like: > > > > $ ip link set can0 type can bitrate 1000000 dbitrate 8000000 fd on tdco 7 tdcf 8 tdc-mode auto > > > > $ ip --details link show can0 > > 1: can0: <NOARP,ECHO> mtu 72 qdisc noop state DOWN mode DEFAULT group default qlen 10 > > link/can promiscuity 0 minmtu 0 maxmtu 0 > > can <FD,TDC_AUTO> state STOPPED (berr-counter tx 0 rx 0) restart-ms 0 > ^^^^^^^^ > This is just the supported mode(s), right? No, this is the active mode. It should display either TDC_AUTO or TDC_MANUAL. If both are displayed as you previously experienced, it is a bug (I will fix). > > bitrate 1000000 sample-point 0.750 > > tq 12 prop-seg 29 phase-seg1 30 phase-seg2 20 sjw 1 brp 1 > > ES582.1/ES584.1: tseg1 2..256 tseg2 2..128 sjw 1..128 brp 1..512 brp_inc 1 > > dbitrate 8000000 dsample-point 0.700 > > dtq 12 dprop-seg 3 dphase-seg1 3 dphase-seg2 3 dsjw 1 dbrp 1 > > tdco 7 tdcf 8 > > ES582.1/ES584.1: dtseg1 2..32 dtseg2 1..16 dsjw 1..8 dbrp 1..32 dbrp_inc 1 > > tdco 0..127 tdcf 0..127 > > clock 80000000 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 > > Is there a way to figure out, which tdc mode is currently active? > > AFAICS just implicitly: > - tdco + tdcv -> manual > - tdco -> automatic > - neither -> off > > correct? If the TDC const values are reported (at least tdco) the controller supports TDC. The flags listed between brackets <FD, TDC_AUTO, CC-LEN8-DLC, ...> are the active flags (this is not only true for TDC but also for all other ctrlmodes). There is no way to know which of the modes are supported. The reason is that netlink only reports can_priv->ctrlmode (c.f. IFLA_CAN_CTRLMODE), not can_priv->ctrlmode_supported. We would need to add a IFLA_CAN_CTRLMODE_SUPPORTED to the netlink interface in order to confirm the supported mode. Currently, the only ways are to either look at the kernel source code or to test the command and see whether it is supported or not. Yours sincerely, Vincent
On Tue.17 Aug 2021 à 01:24, Vincent MAILHOL <mailhol.vincent@wanadoo.fr> wrote: > On Mon. 16 Aug. 2021 at 22:51, Marc Kleine-Budde <mkl@pengutronix.de> wrote: > > On 14.08.2021 19:17:28, Vincent Mailhol wrote: > > > 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. > > > > > > This issue is addressed in ISO 11898-1 section 11.3.3 "Transmitter > > > delay compensation" (TDC). > > > > > > This patch brings command line support to nine TDC parameters which > > > were recently added to the kernel's CAN netlink interface in order to > > > implement TDC: > > > - IFLA_CAN_TDC_TDCV_MIN: Transmitter Delay Compensation Value > > > minimum value > > > - IFLA_CAN_TDC_TDCV_MAX: Transmitter Delay Compensation Value > > > maximum value > > > - IFLA_CAN_TDC_TDCO_MIN: Transmitter Delay Compensation Offset > > > minimum value > > > - IFLA_CAN_TDC_TDCO_MAX: Transmitter Delay Compensation Offset > > > maximum value > > > - IFLA_CAN_TDC_TDCF_MIN: Transmitter Delay Compensation Filter > > > window minimum value > > > - IFLA_CAN_TDC_TDCF_MAX: Transmitter Delay Compensation Filter > > > window maximum value > > > - IFLA_CAN_TDC_TDCV: Transmitter Delay Compensation Value > > > - IFLA_CAN_TDC_TDCO: Transmitter Delay Compensation Offset > > > - IFLA_CAN_TDC_TDCF: Transmitter Delay Compensation Filter window > > > > > > All those new parameters are nested together into the attribute > > > IFLA_CAN_TDC. > > > > > > A tdc-mode parameter allow to specify how to operate. Valid options > > > are: > > > > > > * auto: the transmitter automatically measures TDCV. As such, TDCV > > > values can not be manually provided. In this mode, the user must > > > specify TDCO and may also specify TDCF if supported. > > > > > > * manual: Use the TDCV value provided by the user are used. In this > > > mode, the user must specify both TDCV and TDCO and may also > > > specify TDCF if supported. > > > > > > * off: TDC is explicitly disabled. > > > > > > * tdc-mode parameter omitted (default mode): the kernel decides > > > whether TDC should be enabled or not and if so, it calculates the > > > TDC values. TDC parameters are an expert option and the average > > > user is not expected to provide those, thus the presence of this > > > "default mode". > > > > > > TDCV is always reported in manual mode. In auto mode, TDCV is reported > > > only if the value is available. Especially, the TDCV might not be > > > available if the controller has no feature to report it or if the > > > value in not yet available (i.e. no data sent yet and measurement did > > > not occur). > > > > > > TDCF is reported only if tdcf_max is not zero (i.e. if supported by the controller). > > > > > > For reference, here are a few samples of how the output looks like: > > > > > > $ ip link set can0 type can bitrate 1000000 dbitrate 8000000 fd on tdco 7 tdcf 8 tdc-mode auto > > > > > > $ ip --details link show can0 > > > 1: can0: <NOARP,ECHO> mtu 72 qdisc noop state DOWN mode DEFAULT group default qlen 10 > > > link/can promiscuity 0 minmtu 0 maxmtu 0 > > > can <FD,TDC_AUTO> state STOPPED (berr-counter tx 0 rx 0) restart-ms 0 > > ^^^^^^^^ > > This is just the supported mode(s), right? > > No, this is the active mode. It should display either TDC_AUTO or > TDC_MANUAL. If both are displayed as you previously experienced, > it is a bug (I will fix). > > > > bitrate 1000000 sample-point 0.750 > > > tq 12 prop-seg 29 phase-seg1 30 phase-seg2 20 sjw 1 brp 1 > > > ES582.1/ES584.1: tseg1 2..256 tseg2 2..128 sjw 1..128 brp 1..512 brp_inc 1 > > > dbitrate 8000000 dsample-point 0.700 > > > dtq 12 dprop-seg 3 dphase-seg1 3 dphase-seg2 3 dsjw 1 dbrp 1 > > > tdco 7 tdcf 8 > > > ES582.1/ES584.1: dtseg1 2..32 dtseg2 1..16 dsjw 1..8 dbrp 1..32 dbrp_inc 1 > > > tdco 0..127 tdcf 0..127 > > > clock 80000000 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 > > > > Is there a way to figure out, which tdc mode is currently active? > > > > AFAICS just implicitly: > > - tdco + tdcv -> manual > > - tdco -> automatic > > - neither -> off > > > > correct? > > If the TDC const values are reported (at least tdco) the controller > supports TDC. > > The flags listed between brackets <FD, TDC_AUTO, CC-LEN8-DLC, ...> > are the active flags (this is not only true for TDC but also for > all other ctrlmodes). > > There is no way to know which of the modes are supported. The > reason is that netlink only reports > can_priv->ctrlmode (c.f. IFLA_CAN_CTRLMODE), not > can_priv->ctrlmode_supported. We would need to add a > IFLA_CAN_CTRLMODE_SUPPORTED to the netlink interface in order to > confirm the supported mode. On a second thought, it is actually possible to deduce some of the supported modes (not all) through the can_tdc_const values because tdcv_{min,max} are only reported if CAN_CTRLMODE_TDC_MANUAL is supported. So: - both tdcv_{min,max} and tdco_{min,max} reported -> CAN_CTRLMODE_TDC_MANUAL is supported for sure. CAN_CTRLMODE_TDC_AUTO might or might not be supported. - only tdco_{min,max} reported -> only CAN_CTRLMODE_TDC_AUTO is supported (that's the case for the es58x device). - none reported -> device is not TDC capable. - tdcf_{min,max} reported -> device supports TDCF and the reverse is also true. - other combinations are incorrect and should not be reported. > Currently, the only ways are to either look at the kernel source > code or to test the command and see whether it is supported or > not. > > > Yours sincerely, > Vincent
diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h index 00c763df..258b2d2b 100644 --- a/include/uapi/linux/can/netlink.h +++ b/include/uapi/linux/can/netlink.h @@ -101,6 +101,8 @@ struct can_ctrlmode { #define CAN_CTRLMODE_PRESUME_ACK 0x40 /* Ignore missing CAN ACKs */ #define CAN_CTRLMODE_FD_NON_ISO 0x80 /* CAN FD in non-ISO mode */ #define CAN_CTRLMODE_CC_LEN8_DLC 0x100 /* Classic CAN DLC option */ +#define CAN_CTRLMODE_TDC_AUTO 0x200 /* CAN transiver automatically calculates TDCV */ +#define CAN_CTRLMODE_TDC_MANUAL 0x400 /* TDCV is manually set up by user */ /* * CAN device statistics @@ -134,12 +136,34 @@ enum { IFLA_CAN_BITRATE_CONST, IFLA_CAN_DATA_BITRATE_CONST, IFLA_CAN_BITRATE_MAX, - __IFLA_CAN_MAX -}; + IFLA_CAN_TDC, -#define IFLA_CAN_MAX (__IFLA_CAN_MAX - 1) + /* add new constants above here */ + __IFLA_CAN_MAX, + IFLA_CAN_MAX = __IFLA_CAN_MAX - 1 +}; /* u16 termination range: 1..65535 Ohms */ #define CAN_TERMINATION_DISABLED 0 +/* + * CAN FD Transmitter Delay Compensation (TDC) + */ +enum { + IFLA_CAN_TDC_UNSPEC, + IFLA_CAN_TDC_TDCV_MIN, /* u32 */ + IFLA_CAN_TDC_TDCV_MAX, /* u32 */ + IFLA_CAN_TDC_TDCO_MIN, /* u32 */ + IFLA_CAN_TDC_TDCO_MAX, /* u32 */ + IFLA_CAN_TDC_TDCF_MIN, /* u32 */ + IFLA_CAN_TDC_TDCF_MAX, /* u32 */ + IFLA_CAN_TDC_TDCV, /* u32 */ + IFLA_CAN_TDC_TDCO, /* u32 */ + IFLA_CAN_TDC_TDCF, /* u32 */ + + /* add new constants above here */ + __IFLA_CAN_TDC, + IFLA_CAN_TDC_MAX = __IFLA_CAN_TDC - 1 +}; + #endif /* !_UAPI_CAN_NETLINK_H */ diff --git a/ip/iplink_can.c b/ip/iplink_can.c index e438e416..e698655d 100644 --- a/ip/iplink_can.c +++ b/ip/iplink_can.c @@ -28,6 +28,7 @@ static void print_usage(FILE *f) "\n" "\t[ dbitrate BITRATE [ dsample-point SAMPLE-POINT] ] |\n" "\t[ dtq TQ dprop-seg PROP_SEG dphase-seg1 PHASE-SEG1\n \t dphase-seg2 PHASE-SEG2 [ dsjw SJW ] ]\n" + "\t[ tdcv TDCV tdco TDCO tdcf TDCF ]\n" "\n" "\t[ loopback { on | off } ]\n" "\t[ listen-only { on | off } ]\n" @@ -38,6 +39,7 @@ static void print_usage(FILE *f) "\t[ fd-non-iso { on | off } ]\n" "\t[ presume-ack { on | off } ]\n" "\t[ cc-len8-dlc { on | off } ]\n" + "\t[ tdc-mode { auto | manual | off } ]\n" "\n" "\t[ restart-ms TIME-MS ]\n" "\t[ restart ]\n" @@ -51,6 +53,9 @@ static void print_usage(FILE *f) "\t PHASE-SEG1 := { NUMBER in tq }\n" "\t PHASE-SEG2 := { NUMBER in tq }\n" "\t SJW := { NUMBER in tq }\n" + "\t TDCV := { NUMBER in tc}\n" + "\t TDCO := { NUMBER in tc}\n" + "\t TDCF := { NUMBER in tc}\n" "\t RESTART-MS := { 0 | NUMBER in ms }\n" ); } @@ -105,6 +110,8 @@ static void print_ctrlmode(FILE *f, __u32 cm) _PF(CAN_CTRLMODE_FD_NON_ISO, "FD-NON-ISO"); _PF(CAN_CTRLMODE_PRESUME_ACK, "PRESUME-ACK"); _PF(CAN_CTRLMODE_CC_LEN8_DLC, "CC-LEN8-DLC"); + _PF(CAN_CTRLMODE_TDC_AUTO, "TDC_AUTO"); + _PF(CAN_CTRLMODE_TDC_MANUAL, "TDC_MANUAL"); #undef _PF if (cm) print_hex(PRINT_ANY, NULL, "%x", cm); @@ -116,6 +123,8 @@ static int can_parse_opt(struct link_util *lu, int argc, char **argv, { struct can_bittiming bt = {}, dbt = {}; struct can_ctrlmode cm = {0, 0}; + struct rtattr *tdc; + __u32 tdcv = -1, tdco = -1, tdcf = -1; while (argc > 0) { if (matches(*argv, "bitrate") == 0) { @@ -181,6 +190,18 @@ static int can_parse_opt(struct link_util *lu, int argc, char **argv, NEXT_ARG(); if (get_u32(&dbt.sjw, *argv, 0)) invarg("invalid \"dsjw\" value\n", *argv); + } else if (matches(*argv, "tdcv") == 0) { + NEXT_ARG(); + if (get_u32(&tdcv, *argv, 0)) + invarg("invalid \"tdcv\" value\n", *argv); + } else if (matches(*argv, "tdco") == 0) { + NEXT_ARG(); + if (get_u32(&tdco, *argv, 0)) + invarg("invalid \"tdco\" value\n", *argv); + } else if (matches(*argv, "tdcf") == 0) { + NEXT_ARG(); + if (get_u32(&tdcf, *argv, 0)) + invarg("invalid \"tdcf\" value\n", *argv); } else if (matches(*argv, "loopback") == 0) { NEXT_ARG(); set_ctrlmode("loopback", *argv, &cm, @@ -217,6 +238,23 @@ static int can_parse_opt(struct link_util *lu, int argc, char **argv, NEXT_ARG(); set_ctrlmode("cc-len8-dlc", *argv, &cm, CAN_CTRLMODE_CC_LEN8_DLC); + } else if (matches(*argv, "tdc-mode") == 0) { + NEXT_ARG(); + if (strcmp(*argv, "auto") == 0) { + cm.flags |= CAN_CTRLMODE_TDC_AUTO; + cm.mask |= CAN_CTRLMODE_TDC_AUTO; + } else if (strcmp(*argv, "manual") == 0) { + cm.flags |= CAN_CTRLMODE_TDC_MANUAL; + cm.mask |= CAN_CTRLMODE_TDC_MANUAL; + } else if (strcmp(*argv, "off") == 0) { + cm.mask |= CAN_CTRLMODE_TDC_AUTO | + CAN_CTRLMODE_TDC_MANUAL; + } else { + fprintf(stderr, + "Error: argument of \"tdc-mode\" must be \"auto\", \"manual\" or \"off\", not \"%s\"\n", + *argv); + exit (-1); + } } else if (matches(*argv, "restart") == 0) { __u32 val = 1; @@ -254,6 +292,17 @@ static int can_parse_opt(struct link_util *lu, int argc, char **argv, if (cm.mask) addattr_l(n, 1024, IFLA_CAN_CTRLMODE, &cm, sizeof(cm)); + if (tdcv != -1 || tdco != -1 || tdcf != -1) { + tdc = addattr_nest(n, 1024, IFLA_CAN_TDC | NLA_F_NESTED); + if (tdcv != -1) + addattr32(n, 1024, IFLA_CAN_TDC_TDCV, tdcv); + if (tdco != -1) + addattr32(n, 1024, IFLA_CAN_TDC_TDCO, tdco); + if (tdcf != -1) + addattr32(n, 1024, IFLA_CAN_TDC_TDCF, tdcf); + addattr_nest_end(n, tdc); + } + return 0; } @@ -282,6 +331,62 @@ static void can_print_timing_min_max(const char *json_attr, const char *fp_attr, close_json_object(); } +static void can_print_tdc_opt(FILE *f, struct rtattr *tdc_attr) +{ + struct rtattr *tb[IFLA_CAN_TDC_MAX + 1]; + + parse_rtattr_nested(tb, IFLA_CAN_TDC_MAX, tdc_attr); + if (tb[IFLA_CAN_TDC_TDCV] || tb[IFLA_CAN_TDC_TDCO] || + tb[IFLA_CAN_TDC_TDCF]) { + open_json_object("tdc"); + can_print_nl_indent(); + if (tb[IFLA_CAN_TDC_TDCV]) { + __u32 *tdcv = RTA_DATA(tb[IFLA_CAN_TDC_TDCV]); + + print_uint(PRINT_ANY, "tdcv", " tdcv %u", *tdcv); + } + if (tb[IFLA_CAN_TDC_TDCO]) { + __u32 *tdco = RTA_DATA(tb[IFLA_CAN_TDC_TDCO]); + + print_uint(PRINT_ANY, "tdco", " tdco %u", *tdco); + } + if (tb[IFLA_CAN_TDC_TDCF]) { + __u32 *tdcf = RTA_DATA(tb[IFLA_CAN_TDC_TDCF]); + + print_uint(PRINT_ANY, "tdcf", " tdcf %u", *tdcf); + } + close_json_object(); + } +} + +static void can_print_tdc_const_opt(FILE *f, struct rtattr *tdc_attr) +{ + struct rtattr *tb[IFLA_CAN_TDC_MAX + 1]; + + parse_rtattr_nested(tb, IFLA_CAN_TDC_MAX, tdc_attr); + open_json_object("tdc"); + can_print_nl_indent(); + if (tb[IFLA_CAN_TDC_TDCV_MIN] && tb[IFLA_CAN_TDC_TDCV_MAX]) { + __u32 *tdcv_min = RTA_DATA(tb[IFLA_CAN_TDC_TDCV_MIN]); + __u32 *tdcv_max = RTA_DATA(tb[IFLA_CAN_TDC_TDCV_MAX]); + + can_print_timing_min_max("tdcv", " tdcv", *tdcv_min, *tdcv_max); + } + if (tb[IFLA_CAN_TDC_TDCO_MIN] && tb[IFLA_CAN_TDC_TDCO_MAX]) { + __u32 *tdco_min = RTA_DATA(tb[IFLA_CAN_TDC_TDCO_MIN]); + __u32 *tdco_max = RTA_DATA(tb[IFLA_CAN_TDC_TDCO_MAX]); + + can_print_timing_min_max("tdco", " tdco", *tdco_min, *tdco_max); + } + if (tb[IFLA_CAN_TDC_TDCF_MIN] && tb[IFLA_CAN_TDC_TDCF_MAX]) { + __u32 *tdcf_min = RTA_DATA(tb[IFLA_CAN_TDC_TDCF_MIN]); + __u32 *tdcf_max = RTA_DATA(tb[IFLA_CAN_TDC_TDCF_MAX]); + + can_print_timing_min_max("tdcf", " tdcf", *tdcf_min, *tdcf_max); + } + close_json_object(); +} + static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[]) { if (!tb) @@ -413,6 +518,10 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[]) dbt->phase_seg2); print_uint(PRINT_ANY, "sjw", " dsjw %u", dbt->sjw); print_uint(PRINT_ANY, "brp", " dbrp %u", dbt->brp); + + if (tb[IFLA_CAN_TDC]) + can_print_tdc_opt(f, tb[IFLA_CAN_TDC]); + close_json_object(); } @@ -433,6 +542,10 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[]) can_print_timing_min_max("brp", " dbrp", dbtc->brp_min, dbtc->brp_max); print_uint(PRINT_ANY, "brp_inc", " dbrp_inc %u", dbtc->brp_inc); + + if (tb[IFLA_CAN_TDC]) + can_print_tdc_const_opt(f, tb[IFLA_CAN_TDC]); + close_json_object(); }
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. This issue is addressed in ISO 11898-1 section 11.3.3 "Transmitter delay compensation" (TDC). This patch brings command line support to nine TDC parameters which were recently added to the kernel's CAN netlink interface in order to implement TDC: - IFLA_CAN_TDC_TDCV_MIN: Transmitter Delay Compensation Value minimum value - IFLA_CAN_TDC_TDCV_MAX: Transmitter Delay Compensation Value maximum value - IFLA_CAN_TDC_TDCO_MIN: Transmitter Delay Compensation Offset minimum value - IFLA_CAN_TDC_TDCO_MAX: Transmitter Delay Compensation Offset maximum value - IFLA_CAN_TDC_TDCF_MIN: Transmitter Delay Compensation Filter window minimum value - IFLA_CAN_TDC_TDCF_MAX: Transmitter Delay Compensation Filter window maximum value - IFLA_CAN_TDC_TDCV: Transmitter Delay Compensation Value - IFLA_CAN_TDC_TDCO: Transmitter Delay Compensation Offset - IFLA_CAN_TDC_TDCF: Transmitter Delay Compensation Filter window All those new parameters are nested together into the attribute IFLA_CAN_TDC. A tdc-mode parameter allow to specify how to operate. Valid options are: * auto: the transmitter automatically measures TDCV. As such, TDCV values can not be manually provided. In this mode, the user must specify TDCO and may also specify TDCF if supported. * manual: Use the TDCV value provided by the user are used. In this mode, the user must specify both TDCV and TDCO and may also specify TDCF if supported. * off: TDC is explicitly disabled. * tdc-mode parameter omitted (default mode): the kernel decides whether TDC should be enabled or not and if so, it calculates the TDC values. TDC parameters are an expert option and the average user is not expected to provide those, thus the presence of this "default mode". TDCV is always reported in manual mode. In auto mode, TDCV is reported only if the value is available. Especially, the TDCV might not be available if the controller has no feature to report it or if the value in not yet available (i.e. no data sent yet and measurement did not occur). TDCF is reported only if tdcf_max is not zero (i.e. if supported by the controller). For reference, here are a few samples of how the output looks like: $ ip link set can0 type can bitrate 1000000 dbitrate 8000000 fd on tdco 7 tdcf 8 tdc-mode auto $ ip --details link show can0 1: can0: <NOARP,ECHO> mtu 72 qdisc noop state DOWN mode DEFAULT group default qlen 10 link/can promiscuity 0 minmtu 0 maxmtu 0 can <FD,TDC_AUTO> state STOPPED (berr-counter tx 0 rx 0) restart-ms 0 bitrate 1000000 sample-point 0.750 tq 12 prop-seg 29 phase-seg1 30 phase-seg2 20 sjw 1 brp 1 ES582.1/ES584.1: tseg1 2..256 tseg2 2..128 sjw 1..128 brp 1..512 brp_inc 1 dbitrate 8000000 dsample-point 0.700 dtq 12 dprop-seg 3 dphase-seg1 3 dphase-seg2 3 dsjw 1 dbrp 1 tdco 7 tdcf 8 ES582.1/ES584.1: dtseg1 2..32 dtseg2 1..16 dsjw 1..8 dbrp 1..32 dbrp_inc 1 tdco 0..127 tdcf 0..127 clock 80000000 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 $ ip --details --json --pretty link show can0 [ { "ifindex": 1, "ifname": "can0", "flags": [ "NOARP","ECHO" ], "mtu": 72, "qdisc": "noop", "operstate": "DOWN", "linkmode": "DEFAULT", "group": "default", "txqlen": 10, "link_type": "can", "promiscuity": 0, "min_mtu": 0, "max_mtu": 0, "linkinfo": { "info_kind": "can", "info_data": { "ctrlmode": [ "FD","TDC_AUTO" ], "state": "STOPPED", "berr_counter": { "tx": 0, "rx": 0 }, "restart_ms": 0, "bittiming": { "bitrate": 1000000, "sample_point": "0.750", "tq": 12, "prop_seg": 29, "phase_seg1": 30, "phase_seg2": 20, "sjw": 1, "brp": 1 }, "bittiming_const": { "name": "ES582.1/ES584.1", "tseg1": { "min": 2, "max": 256 }, "tseg2": { "min": 2, "max": 128 }, "sjw": { "min": 1, "max": 128 }, "brp": { "min": 1, "max": 512 }, "brp_inc": 1 }, "data_bittiming": { "bitrate": 8000000, "sample_point": "0.700", "tq": 12, "prop_seg": 3, "phase_seg1": 3, "phase_seg2": 3, "sjw": 1, "brp": 1, "tdc": { "tdco": 7, "tdcf": 8 } }, "data_bittiming_const": { "name": "ES582.1/ES584.1", "tseg1": { "min": 2, "max": 32 }, "tseg2": { "min": 1, "max": 16 }, "sjw": { "min": 1, "max": 8 }, "brp": { "min": 1, "max": 32 }, "brp_inc": 1, "tdc": { "tdco": { "min": 0, "max": 127 }, "tdcf": { "min": 0, "max": 127 } } }, "clock": 80000000 } }, "num_tx_queues": 1, "num_rx_queues": 1, "gso_max_size": 65536, "gso_max_segs": 65535 } ] Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> --- include/uapi/linux/can/netlink.h | 30 +++++++- ip/iplink_can.c | 113 +++++++++++++++++++++++++++++++ 2 files changed, 140 insertions(+), 3 deletions(-)