CDC ACM driver not creating devices under /dev

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX1
1

Hi,

I am working on custom carrier board based on Tx1. I have connected wwan module on pcie bus.
Data path is through pcie and control path through USB.
Pcie is not able to detect the device, getting following error when i issue rescan command to pcie

[17755.497251] pcieport 0000:00:01.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, id=0008(Requester ID)
[17755.510628] pcieport 0000:00:01.0: device [10de:0fae] error status/mask=00004000/00000000
[17755.519258] pcieport 0000:00:01.0: [14] Completion Timeout (First)
root@tegra-ubuntu:/home/ubuntu# [17755.527025] pcieport 0000:00:02.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, id=0010(Requester ID)
[17755.541318] pcieport 0000:00:02.0: device [10de:0faf] error status/mask=00004000/00000000
[17755.549705] pcieport 0000:00:02.0: [14] Completion Timeout (First)

But i see device being detected in USB enumeration.
Also cdc-acm driver is also able to detect device but i could not see the device in /dev
following are the logs
[ 3.989195] usbcore: registered new interface driver cdc_ether
[ 4.006634] usbcore: registered new interface driver cdc_subset
[ 4.024276] usbcore: registered new interface driver cdc_ncm
[ 4.057222] usbcore: registered new interface driver cdc_acm
[ 4.062890] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
[ 4.071114] usbcore: registered new interface driver cdc_wdm
[ 16.695288] cdc_acm 1-4:1.0: This device cannot do calls on its own. It is not a modem.
[ 16.705067] cdc_acm 1-4:1.0: ttyACM0: USB ACM device
[ 16.711061] cdc_acm 1-4:1.2: This device cannot do calls on its own. It is not a modem.
[ 16.719938] cdc_acm 1-4:1.2: ttyACM1: USB ACM device
[ 16.723014] cdc_acm 1-4:1.4: This device cannot do calls on its own. It is not a modem.
[ 16.732108] cdc_acm 1-4:1.4: ttyACM2: USB ACM device
[ 16.746735] cdc_ncm 1-4:1.6 wwan0: register ‘cdc_ncm’ at usb-tegra-xhci-4, Mobile Broadband Network Device (NO ARP), 00:00:11:12:13:14
[ 16.757500] cdc_ncm 1-4:1.8 wwan1: register ‘cdc_ncm’ at usb-tegra-xhci-4, Mobile Broadband Network Device (NO ARP), 00:00:11:12:13:16
[ 16.763879] cdc_ncm 1-4:1.10 wwan2: register ‘cdc_ncm’ at usb-tegra-xhci-4, Mobile Broadband Network Device (NO ARP), 00:00:11:12:13:18
[ 16.770659] cdc_ncm 1-4:1.12 wwan3: register ‘cdc_ncm’ at usb-tegra-xhci-4, Mobile Broadband Network Device (NO ARP), 00:00:11:12:13:1a
[ 25.420638] cdc_ncm 1-4:1.6 wwan0: unregister ‘cdc_ncm’ usb-tegra-xhci-4, Mobile Broadband Network Device (NO ARP)
[ 25.477124] cdc_ncm 1-4:1.8 wwan1: unregister ‘cdc_ncm’ usb-tegra-xhci-4, Mobile Broadband Network Device (NO ARP)
[ 25.547368] cdc_ncm 1-4:1.10 wwan2: unregister ‘cdc_ncm’ usb-tegra-xhci-4, Mobile Broadband Network Device (NO ARP)
[ 25.607291] cdc_ncm 1-4:1.12 wwan3: unregister ‘cdc_ncm’ usb-tegra-xhci-4, Mobile Broadband Network Device (NO ARP)

Does anyone have idea how to resolve this??

Thanks,
Prathamesh

2

Is it the PCIe rescan that you are talking about here?
Can you please give the command used?
Completion timeout suggests that the device is not responding. Although I don’t clearly understand what kind of device is it, are we doing everything that is supposed to be done to make this device respond to requests coming from host?

3

Hi Vidyas

Thanks for replay.
Following is the command I am talking about
echo 1 > /sys/bus/pci/rescan
I have applied patch as mentioned i this post

Is there anything that needs to be changed in device tree?

Thanks,
Prathamesh

4

patyarahate,

Are you using rel-24.2.1 or rel-28.1 now?

5

Hi

I am using rel24.1. is there issue with this release?
Or any patches available

Thanks,
Prathamesh

6

Please try to follow this thread. This should help, though it is based on rel-28.1

7

Hi,

After disabling USB autosuspend, i could get ttyACM devices under /dev directory.
Able to talk to device through ttyACM interface.
I am using rel 24.2.1 only.

Thanks,
Prathamesh