[Ovmsdev] CAN-3 broken again?

Michael Balzer dexter at expeedo.de
Thu Jan 11 07:30:27 HKT 2018


Greg,

please check the receive flow chart, that's not the way the MCP2515 is supposed to work with RXB0CTRL.BUKT=1 and no filters -- if the documentation is correct.

Your change still will produce wrong IncomingFrame() calls caused by the return true from the error handler. You need to change the RxCallback() return type (or
use the frame buffer for an auxiliary result tag) and call loop to add the "don't send but keep calling" case.

Regards,
Michael


Am 10.01.2018 um 23:27 schrieb Greg D.:
> The functioning of buffer overflow, I believe, is working as it should. 
> I see that most of the time, frames come in on buffer 0.  When I cause
> the overflow by starting wifi, I see a single frame received in buffer
> 1, along with the status of a buffer overflow from buffer 0, but the
> interrupt status only shows buffer 1 as being full: status from register
> 2C is 0x22, not 0x23.  The error status was 0x40, indicating the single
> overflow, as expected.  My guess is that the timing is such that buffer
> 0 was being read at the time the next frame arrived, so it went into
> buffer 1, and that buffer 0 had emptied by the time buffer 1's interrupt
> was seen.  I have not seen a buffer 1 overflow (which would indicate
> that a frame was actually lost), so the buffer 0 overflow is totally not
> an issue.  At most, it's a warning that the system is under load.  No
> surprise there; it was.

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