When using the tcan4x5x under high load of both RX/TX interrupts, at some point the nINT signal stays asserted, causing the socket to block in user space. This reproduces very reliably (in my system) when both reading/writing at 1ms intervals at CAN bus speed 1Mbps. When it occurs, M_CAN_IR is set to 0x580d and never recovers (causing nINT to stay asserted). The problem does not occur when only reading or only writing. After checking the m_can_isr() function from drivers/net/can/m_can/m_can.c, I noticed that MCAN interrupts are disabled while processing the IR_RF0N flag, but not while processing IR_TEFN. I'm not sure why, aren't both handlers running from the same interrupt context and communicating to MRAM via SPI? I'm running kernel version 5.4.24 but I can see that in e.g. 5.17.0 this still applies. When I disable interrupts during IR_TEFN handling, the blocking socket / nINT issue is gone. Met vriendelijke groet / Kind regards, Wouter van Herpen Designer
