Hello everybody, my colleague at Elektroline.cz works on design of iMX6 based system with CAN FD support realized by tcan4x5x chip connected to eCSPI. It seems that there are problems with eCSPI DMA stucks and other troubles. When the same chip (or even Microchip's mcp251xfd) is connected to other (less industry sound platforms) as Allwinner etc... drivers seems to work reliably, but tests on iMX6 results in failures. They consider fast redesign to slCAN connected second Microchip MCU to resolve critical problem for the project now.... The setup on 5.7 kernel partially wrks Linux RAPTOR 5.7.8 #2 SMP Fri Oct 30 18:55:02 CET 2020 armv7l GNU/Linux &ecspi1 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_raptor_ecspi1>; cs-gpios = <&gpio2 30 0> ; status = "okay"; tcan4550: tcan4x5x@0 { compatible = "ti,tcan4x5x"; reg = <0>; #address-cells = <1>; #size-cells = <1>; spi-max-frequency = <16000000>; bosch,mram-cfg = <0x0 0 0 32 0 0 1 1>; interrupt-parent = <&gpio5>; interrupts = <4 GPIO_ACTIVE_LOW>; device-wake-gpios = <&gpio2 16 GPIO_ACTIVE_LOW>; }; }; Transmit test cangen can1 -g 5 -I 123 -n100 OK cangen can1 -g 3 -I 123 -n100 write: No buffer space available [ 857.829179] tcan4x5x spi0.0 can1: hard_xmit called while tx busy [ 857.836124] tcan4x5x spi0.0 can1: hard_xmit called while tx busy [ 857.842537] tcan4x5x spi0.0 can1: hard_xmit called while tx busy [ 857.852634] NOHZ: local_softirq_pending 08 [ 857.862952] NOHZ: local_softirq_pending 08 Receive test cangen can0 -g 5 -I 123 -n100 OK cangen can0 -g 3 -I 123 -n100 [ 1161.348615] tcan4x5x spi0.0 can1: msg lost in rxf0 [ 1161.355672] tcan4x5x spi0.0 can1: msg lost in rxf0 [ 1161.362845] tcan4x5x spi0.0 can1: msg lost in rxf0 [ 1161.369976] tcan4x5x spi0.0 can1: msg lost in rxf0 [ 1161.377074] tcan4x5x spi0.0 can1: msg lost in rxf0 [ 1161.384021] tcan4x5x spi0.0 can1: msg lost in rxf0 [ 1161.391211] tcan4x5x spi0.0 can1: msg lost in rxf0 [ 1161.398338] tcan4x5x spi0.0 can1: msg lost in rxf0 [ 1161.405299] tcan4x5x spi0.0 can1: msg lost in rxf0 [ 1161.412445] tcan4x5x spi0.0 can1: msg lost in rxf0 [ 1161.419680] tcan4x5x spi0.0 can1: msg lost in rxf0 ... the 5.10 RT (preffered) and non-RT seems to be completely broken Linux RAPTOR 5.10.19 #6 SMP Tue Mar 9 13:29:28 CET 2021 armv7l GNU/Linux &ecspi1 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_raptor_ecspi1>; cs-gpios = <&gpio2 30 0> ; status = "okay"; tcan4550: tcan4x5x@0 { compatible = "ti,tcan4x5x"; reg = <0>; #address-cells = <1>; #size-cells = <1>; spi-max-frequency = <16000000>; bosch,mram-cfg = <0x0 0 0 32 0 0 1 1>; interrupt-parent = <&gpio5>; interrupts = <4 GPIO_ACTIVE_LOW>; device-wake-gpios = <&gpio2 16 GPIO_ACTIVE_LOW>; }; }; Transmit test, only one message transmited. cangen can1 -g 100 -I 123 -n100 write: No buffer space available candump can0 can0 123 [8] 06 56 C6 01 AF E3 B6 4A Receive test no messages received [ 332.449605] tcan4x5x spi0.0 can1: msg lost in rxf0 We can rebuild kernel, test patches, try to investgate what happens. All suggestions what to test and what can be cause welcomed. Thanks in advance, Pavel -- Pavel Pisa phone: +420 603531357 e-mail: pisa@xxxxxxxxxxxxxxxx Department of Control Engineering FEE CVUT Karlovo namesti 13, 121 35, Prague 2 university: http://dce.fel.cvut.cz/ company: https://www.pikron.com/ personal: http://cmp.felk.cvut.cz/~pisa projects: https://www.openhub.net/accounts/ppisa CAN related:http://canbus.pages.fel.cvut.cz/