From mboxrd@z Thu Jan 1 00:00:00 1970 From: mkl@pengutronix.de (Marc Kleine-Budde) Date: Mon, 04 Aug 2014 16:27:49 +0200 Subject: [PATCH v3 4/4] can: flexcan: add vf610 support for FlexCAN In-Reply-To: References: <53C5398F.2000005@pengutronix.de> <1b8a8ca03b4a160027a79b722f697e25@agner.ch> <601adb6fe47279c115c1cc607365a00e@agner.ch> <53D25C9D.5080803@pengutronix.de> <53D67A46.3060202@pengutronix.de> <53D8DB3D.7030403@pengutronix.de> Message-ID: <53DF9865.9060407@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 08/04/2014 03:43 PM, Stefan Agner wrote: [...] >> Thanks for the test, so far looks promising :) With this setup the other >> CAN node repeats the CAN frame until it's ACKed. Because there is no >> node with a compatible bitrate, there is no ACking CAN node. >> >> Can you add a third CAN node to the network. The second and third node >> should use the same bitrate, while your vf610 uses a different one. With >> the new setup it should take more than one frame until the vf610 goes >> into error warning and even more frames to error passive. This way we >> can see it the error warning interrupt is connected or not. The error >> counters should increase with each "wrong" bitrate frame it sees, you >> can check with: >> >> ip -details link show can0 >> >> The output looks like this: >> >>> 4: can0: mtu 16 qdisc pfifo_fast state UNKNOWN mode DEFAULT qlen 10 >>> link/can >>> can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0 >> ^^^^^^^^^^^^^^^^^^^^^^ >>> bitrate 1000000 sample-point 0.750 >>> tq 125 prop-seg 2 phase-seg1 3 phase-seg2 2 sjw 1 >>> sja1000: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1 >>> clock 8000000 >> >> When one of the berr-counter crosses 96 (and stays below 128) a warning >> interrupt should be generated. > > Ok, created this setup, could successfully communicate with all three > nodes. I then set the Vybrid to half of the bitrate. When I send a frame > from Vybrid, the berr-counter tx immediately ends up at 128 and the > device is in ERROR-PASSIVE: This is expected. > root at colibri-vf:~# ip -details link show can1 > 3: can1: mtu 16 qdisc pfifo_fast state UNKNOWN > mode DEFAULT group default qlen 10 > link/can promiscuity 0 > can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0 > bitrate 124990 sample-point 0.739 > tq 347 prop-seg 8 phase-seg1 8 phase-seg2 6 sjw 1 > flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1 > clock 83368421 ^^^^^^^^ BTW: the can core has a really weird clock rate, have a look at the datasheet if you manage to route a 24 MHz clock (or another multiple of 8MHz) to the flexcan core. I had a quick glance at the datasheet, if I understand it correctly the Fast OSC clock runs with 24 MHz. > root at colibri-vf:~# cansend can1 1F334455#1122334455667788 > interface = can1, family = 29, type = 3, proto = 1 > root at colibri-vf:~# [ 818.886664] flexcan_irq, esr=00062242 > [ 818.890365] flexcan_irq, ctrl=1c3dac57 > > root at colibri-vf:~# ip -details link show can1 > 3: can1: mtu 16 qdisc pfifo_fast state UNKNOWN > mode DEFAULT group default qlen 10 > link/can promiscuity 0 > can state ERROR-PASSIVE (berr-counter tx 128 rx 0) restart-ms 0 > bitrate 124990 sample-point 0.739 > tq 347 prop-seg 8 phase-seg1 8 phase-seg2 6 sjw 1 > flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1 > clock 83368421 > > > When I send the frames from another device on the bus, I can see the rx > count incrementing by one on each frame I send. As you expected, the > device changes to ERROR-WARNING when crossing the 96 frame boundary: This is correct > root at colibri-vf:~# ip -details link show can1 > 3: can1: mtu 16 qdisc pfifo_fast state UNKNOWN > mode DEFAULT group default qlen 10 > link/can promiscuity 0 > can state ERROR-ACTIVE (berr-counter tx 0 rx 92) restart-ms 0 > bitrate 124990 sample-point 0.739 > tq 347 prop-seg 8 phase-seg1 8 phase-seg2 6 sjw 1 > flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1 > clock 83368421 > root at colibri-vf:~# [ 448.331150] flexcan_irq, esr=0005050a > [ 448.334851] flexcan_irq, ctrl=1c3dac57 > ip -details link show can1 > 3: can1: mtu 16 qdisc pfifo_fast state UNKNOWN > mode DEFAULT group default qlen 10 > link/can promiscuity 0 > can state ERROR-WARNING (berr-counter tx 0 rx 102) restart-ms 0 > bitrate 124990 sample-point 0.739 > tq 347 prop-seg 8 phase-seg1 8 phase-seg2 6 sjw 1 > flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1 > clock 83368421 > However, once reaching 128, I don't get another interrupt and the device > stays in ERROR-WARNING: The contents of the esr reg would be interesting, especially the FLT_CONF part. > 3: can1: mtu 16 qdisc pfifo_fast state UNKNOWN > mode DEFAULT group default qlen 10 > link/can promiscuity 0 > can state ERROR-WARNING (berr-counter tx 0 rx 128) restart-ms 0 > bitrate 124990 sample-point 0.739 > tq 347 prop-seg 8 phase-seg1 8 phase-seg2 6 sjw 1 > flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1 > clock 83368421 > > Is this the expected behavior on receive? No, it should go into error passive if one of the error counters have > 127. Maybe this is an error onthe vf610, maybe it's a general flexcan problem. Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 242 bytes Desc: OpenPGP digital signature URL: