On Mon, Jan 18, 2010 at 8:40 AM, Brian Murphy <[email protected]> wrote: >> >> > > I can back this up. We have decided not to use mcp2515 because of packet > loss > on our board. >
Hi, out of curiosity what architecture have you worked on? With the mcp2515 there are good chances that you can keep up with a full stream (because of the 10 mhz SPI interface and, most important, the ability to send an entire Rxed CAN packet in a row). Anyway I fully support Wolfgang's claims about performance. Unfortunately the SPI infrastructure is rather critical and on some architectures it's just plain bad. For example on S3C24XX setting DMA up takes ages and the shift register is 1 byte deep for IRQ mode, so the best option you have is just wait every single transfer to finish with an overall decrease in processor throughput. Another problem is that the best SPI drivers aren't always in the kernel mainline. As far as the mcp251x driver is concerned, now that it is in the mainline, I'm looking forward to substitute worqueues with threaded interrupts (which is something we all have to get used to sooner or later) and adding hardware level CAN-address filtering. Both of these could make it more useful. -- Christian Pellegrin, see http://www.evolware.org/chri/ "Real Programmers don't play tennis, or any other sport which requires you to change clothes. Mountain climbing is OK, and Real Programmers wear their climbing boots to work in case a mountain should suddenly spring up in the middle of the computer room." _______________________________________________ Socketcan-core mailing list [email protected] https://lists.berlios.de/mailman/listinfo/socketcan-core
