Hi
I was working without any problem with a MODEM connected via /dev/ttyACM* to my IMX6ULL in aour custom board.
I executed a reboot on the processor without switch off (both MODEM and IMX6ULL)
the /dev/ttyACM* didn't coming up :-(
Any suggestion?
Thanks
Fabio
thanks Igor ... but it is not so easy to make a reset to external modem ..
in working condition I see the 6 virtual port on /dev/ttyACM* associated to USB port seen
with lsusb command
Bus 001 Device 004: ID 1546:1102 U-Blox AG
in not working condition this USB port is not present
I tried a restart of udev but withou success
Do you have a suggestion to restart the USB service?
thanks
Fabio
After some analysis, I see with normal working ... power on
lsusb
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 1546:1102 U-Blox AG
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
ls /sys/bus/usb/drivers
asix cdc_ether pegasus usbfs
ath3k cdc_ncm r8152 usbhid
ax88179_178a cdc_subset rtl8150 zaurus
bcm203x hub usb
btusb kaweth usb-storage
cdc_acm net1080 usb_ehset_test
ls /sys/bus/usb/drivers/cdc_acm
1-1:1.0 1-1:1.11 1-1:1.2 1-1:1.5 1-1:1.8 module uevent
1-1:1.1 1-1:1.12 1-1:1.3 1-1:1.6 1-1:1.9 new_id unbind
1-1:1.10 1-1:1.13 1-1:1.4 1-1:1.7 bind remove_id
And with not working situation, the cdc_acm drivers is not up and then also
Bus 001 Device 003: ID 1546:1102 U-Blox AG
does not come up ..
During the reboot actions, the log has this error:
usb 1-1: device no response, device descriptor read/64, error -71
but I'm not able to power down/off the modem connected to usb ...
Any suggestions?
Thanks
one can try to disable usb module and its clocks, then reenable again.
Best regards
igor
how is it possible by software?
it is usb clock in CCM_CCGR6 register, usb registers described in
Table 56-34. Default Values of Operational Register Space
thanks,
resolved via modem hardware reset
Hi Fabio
rebooting board without short removing board power may leave some modules
in non-reset state. So reinitialization after reboot will not correctly configure them.
In general one can try to compare usb registers in working and not working (after reboot) case
and perform additional resets (if possible) for external devices like modems.
Best regards
igor
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