Peak-linux-driver-8.14.0 not working

[Magnus.Z]

Hi, I am installing pcan driver for linux in our raspberry pi compute module 4 that has "Debian GNU/Linux 11 (bullseye)". Ther kernel is 5.15.32-v8+

We followed the guide in this link: viewtopic.php?f=59&t=6897&sid=0d035991e ... 10ca1be8c9

"sudo make install" and "sudo modprobe pcan" went well. However when we are running "dmesg | grep pcan" we are getting the following output:

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evoy@raspberrypi:~/peak-linux-driver-8.14.0 $ dmesg | grep pcan 
[    4.477943] pcan: loading out-of-tree module taints kernel.
[    4.506656] pcan: Release_20220124_n (le)
[    4.506688] pcan: driver config [mod] [pci] [pec] [usb] [net] 
[    4.507393] pcan 0000:01:00.0: enabling device (0000 -> 0002)
[    4.507425] pcan 0000:01:00.0: PCAN-M.2 sub-system id 14h (4 channels)
[    4.628624] pcan: PCAN-M.2: flash write failure (err -16)
[    4.628671] pcan: PCB v2h FPGA v3.2.1 (mode 3)
[    4.628783] pcan 0000:01:00.0: pcan: Rx dma_alloc_coherent(4096) failure
[    4.628856] pcan: probe of 0000:01:00.0 failed with error -12
[    4.629288] usbcore: registered new interface driver pcan
[    4.629324] pcan: major 510.

We have an pci device connected to the raspberry pi. Can you help us with this issue?

[S.Grosjean]

Hi,

The PCAN M2 card needs to share DMA areas between the host and the card: for each CAN, the driver requests 2 x 4KB of such DMA area. It looks like your system lacks of such space.

Please have a look to topics that talk about tuning DMA for RPI4 (for example: https://forums.raspberrypi.com/viewtopic.php?t=285068).

Regards,

[Magnus.Z]

Thanks for your answer. We took a look about how tuning DMA for RPI4. After a period of searching, we found this link https://gist.github.com/geerlingguy/9d7 ... 54417429df where is mentioned how to configure the DMA size in "/boot/bcm2711-rpi-cm4.dtb" file. We have found the place where we should change the size in this file:

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scb {
		compatible = "simple-bus";
		#address-cells = <0x02>;
		#size-cells = <0x02>;
		ranges = <0x0 0x7c000000  0x0 0xfc000000  0x0 0x03800000>, <0x0 0x40000000  0x0 0xff800000  0x0 0x00800000>,  <0x6 0x00000000  0x6 0x00000000  0x2 0x00000000>, <0x0 0x00000000  0x0 0x00000000  0x0 0xfc000000>;
		dma-ranges = <0x00 0x00 0x00 0x00 0x04 0x00>;
		phandle = <0xde>;

		pcie@7d500000 {
			compatible = "brcm,bcm2711-pcie";
			reg = <0x00 0x7d500000 0x00 0x9310>;
			device_type = "pci";
			#address-cells = <0x03>;
			#interrupt-cells = <0x01>;
			#size-cells = <0x02>;
			interrupts = <0x00 0x93 0x04 0x00 0x94 0x04>;
			interrupt-names = "pcie\0msi";
			interrupt-map-mask = <0x00 0x00 0x00 0x07>;
			interrupt-map = <0x00 0x00 0x00 0x01 0x01 0x00 0x8f 0x04 0x00 0x00 0x00 0x02 0x01 0x00 0x90 0x04 0x00 0x00 0x00 0x03 0x01 0x00 0x91 0x04 0x00 0x00 0x00 0x04 0x01 0x00 0x92 0x04>;
			msi-controller;
			msi-parent = <0x2c>;
			ranges = <0x02000000 0x0 0x00000000 0x6 0x00000000 0x2 0x00000000>;
			dma-ranges = <0x2000000 0x00 0x00 0x00 0x00 0x00 0xc0000000>;
			brcm,enable-ssc;
			brcm,enable-l1ss;
			phandle = <0x2c>;

			pci@0,0 {
				device-type = "pci";
				#address-cells = <0x03>;
				#size-cells = <0x02>;
				ranges;
				reg = <0x00 0x00 0x00 0x00 0x00>;
			};
		};

We tried different values for "#size-cells" but we are not getting this right. Do you have any advice after our searching?



Regards,
Magnus

[Magnus.Z]

UPDATE!

We have changed the value of #size-cells in pcie@7d500000 struct from <0x02> to <0x04> and reboot the RPI4 that has raspbian 64bit and installed PCAN driver again. The output of "dmesg | grep pcan" is the following:

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evoy@raspberrypi:~/peak-linux-driver-8.14.0 $ dmesg | grep pcan
[   79.742391] pcan: loading out-of-tree module taints kernel.
[   79.744699] pcan: Release_20220124_n (le)
[   79.744717] pcan: driver config [mod] [pci] [pec] [usb] 
[   79.746283] usbcore: registered new interface driver pcan
[   79.746312] pcan: major 509.

We still can not see the connected device:

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evoy@raspberrypi:~/peak-linux-driver-8.14.0 $ ls -l /dev/pcan* | grep "^c"
ls: cannot access '/dev/pcan*': No such file or directory
evoy@raspberrypi:~/peak-linux-driver-8.14.0 $ ls -l /dev/pcan*
ls: cannot access '/dev/pcan*': No such file or directory

Do you have any advice that can help us after this update?

Regards,
Magnus

[S.Grosjean]

Hello,

Looks like the M2 card is no more detected at all. You should at least see what you had before, that is:

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[    4.507393] pcan 0000:01:00.0: enabling device (0000 -> 0002)
[    4.507425] pcan 0000:01:00.0: PCAN-M.2 sub-system id 14h (4 channels)
[    4.628624] pcan: PCAN-M.2: flash write failure (err -16)
[    4.628671] pcan: PCB v2h FPGA v3.2.1 (mode 3)

Regards,

[S.Grosjean]

Hello,

FYI the mainline kernel includes for years now the peak_pciefd socket-can driver that is in charge to handle the PCAN M.2 card too.

I would also strongly suggest to configure its use in your kernel configuration (Networking support -> CAN bus subsystem support -> CAN Device Drivers -> PEAK-System PCAN-PCIe FD cards).

[Magnus.Z]

Hello again Stéphane,

We are already using the socket-can driver, but we want to use the chardev. We have tested the chardev with RPI cm4 with 32bit OS and it is working. The issue appeared when we tried using the same hardware but with 64bit OS.

We tried tuning the DMA but it was not successful. Where we should change the DMA size? and what we have to change it to?



Regards,
Magnus

[S.Grosjean]

Hello,

This is important information that will allow us to move forward on this issue. So, to summarize, you confirm that under 5.15.32 the PCAN-M2:

• works with the socket-can driver in 32-bit and 64-bit modes
• works with the 32-bit pcan driver
• does not work with the 64-bit pcan driver

Right?

[Magnus.Z]

Under 5.15.32-v8+ 64bit the PCAN-M2:

• does not work with the socket-can and pcan driver

Under 5.15.32-v7l+ 32bit the PCAN-M2:

• works with the socket-can and the pcan driver

Regards,
Magnus

[M.Maidhof]

Updating the PCAN-M.2 card to the latest firmware 3.5.6 did solve the issue in the 64bit ARM environment.

regards

Michael