Hi Wolfgang,

On 03/17/2017 01:04 PM, Wolfgang Grandegger wrote:

Hm, that's unusual. Cable disconnected and then send a message:

$ grep /proc/interrupts; sleep 10; /proc/interrupts

should make things clear. But maybe it's a clever chip and it does stop
sending error messages if the error counter does not change any more.
After bus-off, the chip is quiet, of course. Should have a closer look
to the CAN standard.

The interrupt count does not increment after device reaches
tx-error-passive (with cable disconnected).

# while true; do grep -i hi3110 /proc/interrupts; sleep 10; done &
[1] 793
#
111:          0          0  gpio-mxc  12 Edge      hi3110
# candump -t d -e any,0:0,#FFFFFFF &
[2] 798
# cansend can0 123#
#
 (000.000000)  can0  20000004   [8]  00 08 00 00 00 00 60 00   ERRORFRAME
	controller-problem{tx-error-warning}
	error-counter-tx-rx{{96}{0}}
 (000.002122)  can0  20000004   [8]  00 20 00 00 00 00 80 00   ERRORFRAME
	controller-problem{tx-error-passive}
	error-counter-tx-rx{{128}{0}}
111:         10          0  gpio-mxc  12 Edge      hi3110
111:         10          0  gpio-mxc  12 Edge      hi3110
111:         10          0  gpio-mxc  12 Edge      hi3110

quoted

quoted

So far using NAPI was mandatory. There is the problem of out-of-order
message reception if handled in the isr on multi processor systems.
Marc, what is the current policy?

Since this is a SPI based CAN, I am wary for any additional latencies
NAPI might introduce. The RX handling is being done at the very
beginning of the ISR for this reason.

Can we go ahead with the existing implementation and re-visit this at a
later time?

Likely yes, as Marc has already reviewed the driver once.

Thanks, I will go ahead and submit v4 patch.

BTW: what system board/processor are you using?

It is a custom board using Phytec phyFLEX-i.MX6 Dual SOM.
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html