I think, I understand the problem.
I have an asynchronism with “mdev” and the /dev/ttyUSB0 is destroyed just after being initialized.
The last test.
INFO: QDL Port : /dev/ttyUSB0
INFO: Device Path: /dev/cdc-wdm0
INFO: FW Path : /usr/wit/applic/update/
Target image Info:
Carrier :SIERRA
FW Version :00.08.07.00
Model ID :SWI9X07H
Package ID :000
PRI Version:000.057
SKU :9999999
Modem is in QDL mode. Continuing FW download
Waiting for modem to come up in BOOT and HOLD mode …
BOOT and HOLD Mode. Downloading firmware …
Downloading: /usr/wit/applic/update//RC76xx_Release8_SIERRA_R2C_7620.spk
/
FW download succeeded.
Waiting for modem to come up in ONLINE mode …
Modem is now in ONLINE mode …
Many thanks for your important help.
sorry if my English is not perfect. it is not my native language.
Now I just have to automate it.