On 16.04.2023 14:33:11, Oliver Hartkopp wrote: > > > On 4/14/23 20:20, Marc Kleine-Budde wrote: > > On 13.04.2023 17:30:51, Judith Mendez wrote: > > > Add a hrtimer to MCAN struct. Each MCAN will have its own > > > hrtimer instantiated if there is no hardware interrupt found. > > > > > > The hrtimer will generate a software interrupt every 1 ms. In > > > > Are you sure about the 1ms? I had the 5ms that are actually used in the code in mind. But this is a good calculation. > The "shortest" 11 bit CAN ID CAN frame is a Classical CAN frame with DLC = 0 > and 1 Mbit/s (arbitration) bitrate. This should be 48 bits @1Mbit => ~50 > usecs > > So it should be something about > > 50 usecs * (FIFO queue len - 2) Where does the "2" come from? > if there is some FIFO involved, right? Yes, the mcan core has a FIFO. In the current driver the FIFO configuration is done via device tree and fixed after that. And I don't know the size of the available RAM in the mcan IP core on that TI SoC. Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung Nürnberg | Phone: +49-5121-206917-129 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 |
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