Re: CM-ITC, pch_can/c_can_pci, sendto() returning ENOBUFS - Marc Kleine-Budde

From: Marc Kleine-Budde <mkl@pengutronix.de>
To: Jacob Kroon <jacob.kroon@gmail.com>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>,
	linux-can@vger.kernel.org, wg@grandegger.com
Subject: Re: CM-ITC, pch_can/c_can_pci, sendto() returning ENOBUFS
Date: Mon, 5 Sep 2022 17:54:16 +0200	[thread overview]
Message-ID: <20220905155416.pgvseb6uggc67ua4@pengutronix.de> (raw)
In-Reply-To: <0eb1dd1b-427a-92c5-22ef-97c557cfec6e@gmail.com>

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On 01.09.2022 11:38:31, Jacob Kroon wrote:
> I used "candump can0 -l" on the EG20T host to capture the traffic, and
> then connected an CAN USB analyzer to the network and used that to
> capture the traffic. One thing sticks out. This is the log from the
> CAN USB analyzer:

Who generates these CAN messages?

> > ...
> > 505.7052;RX;0x464;3;0x01;0x01;0x00;;;;;;
> > 505.7052;RX;0x464;3;0x00;0x00;0x00;;;;;;
> > 505.7063;RX;0x65;64;;;;;;;;;

As Oliver pointed out, this doesn't look like a valid CAN frame. Is the
analyzer and/or sender configured for CAN-FD?

> > 505.7662;RX;0x440;3;0x32;0x20;0xFA;;;;;;
> > 505.7912;RX;0x44C;3;0x35;0x20;0xFA;;;;;;
> > 505.9632;RX;0x464;3;0x00;0x00;0x00;;;;;;
> > 505.9632;RX;0x464;3;0x01;0x01;0x00;;;;;;
> > 505.9752;RX;0x468;3;0x51;0x20;0xFA;;;;;;
> > 506.0362;RX;0x440;3;0x32;0x20;0xFA;;;;;;
> > 506.0622;RX;0x44C;3;0x35;0x20;0xFA;;;;;;
> > 506.2112;RX;0x464;3;0x00;0x00;0x00;;;;;;
> > 506.2112;RX;0x464;3;0x00;0x00;0x00;;;;;;
> > 506.2462;RX;0x468;3;0x51;0x20;0xFA;;;;;;
> > 506.3072;RX;0x440;3;0x32;0x20;0xFA;;;;;;
> > 506.3322;RX;0x44C;3;0x35;0x20;0xFA;;;;;;
> > 506.4572;RX;0x464;3;0x00;0x00;0x00;;;;;;
> > 506.4580;RX;0x464;3;0x00;0x00;0x00;;;;;;
> > 506.5162;RX;0x468;3;0x51;0x20;0xFA;;;;;;
> > 522.7203;RX;0x1E;1;0xFF;;;;;;;;
> > ...
> 
> Note the third message from the top. This is what "candump" on the host
> logs:
> 
> > ...
> > (1662022485.638794) can0 464#010100
> > (1662022485.638940) can0 464#000000
> > (1662022485.699405) can0 440#3220FA
> > (1662022485.725166) can0 44C#3520FA
> > (1662022485.896858) can0 464#000000
> > (1662022485.897382) can0 464#010100
> > (1662022485.909042) can0 468#5120FA
> > (1662022485.970036) can0 440#3220FA
> > (1662022485.995596) can0 44C#3520FA
> > (1662022486.144685) can0 464#000000
> > (1662022486.144768) can0 464#000000
> > (1662022486.179595) can0 468#5120FA
> > (1662022486.240561) can0 440#3220FA
> > (1662022486.266274) can0 44C#3520FA
> > (1662022486.391248) can0 464#000000
> > (1662022486.391469) can0 464#000000
> > (1662022486.450115) can0 468#5120FA
> > (1662022502.662035) can0 01E#FF
> > ...
> 
> It fails to see the 3rd message from the previous log. What would that
> indicate ? The CAN analyzer sees the message, but the EG20T doesn't.

Is this error somehow related to the "can0: can_put_echo_skb: BUG!
echo_skb 0 is occupied"?

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
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