Re: [PATCH] can: ctucanfd: ctucan_err_interrupt(): do not emit info messages on Arbitration Lost or CAN Bus Error IRQs

[Marc Kleine-Budde]

On 15.08.2026 01:02:34, Pavel Pisa wrote:
> Acked-by: Pavel Pisa <pisa@xxxxxxxxxxx>

Thanks

> In the fact, I am in doubts if ALI Arbitration lost interrupt
> should be enabled even by CAN_CTRLMODE_BERR_REPORTING unconditionally.

ACK

> There are lot of situations when error reporting is valuable
> but overhead of arbitration lost could load system quite lot.

ACK

> But on the other hand SocketCAN does not provide separate
> reporting option to enable can_stats.arbitration_lost
> updates

If needed, this option can be added.

> so current code in ctucan_chip_start is proper option

So I'm thinking of sending a patch to disable the arbitration lost IRQ.

>
>
> 	if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
> 		int_ena |= REG_INT_STAT_ALI |
> 			   REG_INT_STAT_BEI;
> 	}


> PS1: I have been on vacations without e-mail and I will be next
> week too, so sorry for possible delays and these PSs to
> wrap up quickly what seems on hold before my leave.

Enjoy your leave and e-mail free time!

> PS2: Marc and others, please, can you confirm if my patch
> "docs: ctucanfd: fix swapped colors in legend for TX buffer FSM of CTU CAN FD"
> https://lore.kernel.org/linux-can/d775feefa1c16d7ea7f42482483c81491f75ce6c.1785574572.git.pisa@xxxxxxxxxxxxxxxx/
> is on the right track or if I should repost it to somebody
> other than Randy Dunlap and linux-doc to reach right
> documentation maintainers.

I've included it in yesterdays^w todays PR.

> PS3: Marc, please, have you received my question about problems
> with CAN FD on iMX8plus CompuLab's IOT-DIN-IMX8PLUS.

yes

> Even manual specifies it as Std CAN only... Can it be
> related to some SoC problems, even much lowered speeds
> do not help so probably not transceiver HW, may be missing
> information for TDC in DTS???

The flexcan driver is not attached to the kernel's TDC infrastructure.
Maybe it needs some improvements.

> PS4: LPC and Open Source Summit Europe will be held in Prague.

I'll be there for LPC and E-OSS.

> Our submissions to OSSE have not been accepted, one
> is on wait list still. Price is too high for my budget
> when I bring open technology to others. I am not sure about LPC,
> I consider to pay for Real-Time and Scheduling microconference
> or something like that. I could presnet something about our mainline
> and RT CAN latency testing or our other RT, RISC-V embedded
> knowledge if there is interest and suggestion for miniconference, BoF,
> so then I would be allowed. Anyway if you have interest to meet,
> I will be in Prague and when not teaching, I will be happy to
> reserve time. There would be real local enthusiast, free community
> and access conference before these Linux Foundation ones
>
> https://www.linuxdays.cz/2026/
>
> I expect to show our HW ZOO there on the booth there as usual
> so you can visit us at our university ground.

I will arrive on Sunday, but I haven't booked a train yet. When does the
conference close on Sunday?

> If there is interest in some community open and free access
> meeting then I can negotiate lecture hall, computer rooms etc.
> at our faculty when they are not used for teaching or other
> events. For something relay interesting which fits in weekend
> October 3-4, I would consider even abandon part pr whole of my
> LinuxDays presence. No chance to meet during weekend after LPC
> and next days, I have already taken these by Apache/NuttX conference
> in Glasgow where we present our projects including Matlab Simulink
> target for NuttX (and Linux).

regards,
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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