Hi, @jyijyi , thanks for your answer.
I have succesfully kick module into download mode by asserting (low-level) TP1 pin at power on.
Now RC7620 device doesn’t dissapear from usb bus and only one serial port is present (/dev/ttyUSB0).
Then I deassert TP1 pin and try to download firmware but it doesn’t work… says “error: unsupported download protocol”:
root@XXXXXXX:~# qmi-firmware-update -t /dev/ttyUSB0 --update-download RC76xx_Release9_GENERIC_GCF_7620.spk -v
[01 Jun 2023, 17:56:42] [Debug] [qfu-udev] sysfs path for ‘ttyUSB0’ found: /sys/devices/platform/soc@0/32f10108.usb/38200000.dwc3/xhci-hcd.2.auto/usb3/3-1
[01 Jun 2023, 17:56:42] [Debug] [qfu-helpers] peer port for ‘/sys/devices/platform/soc@0/32f10108.usb/38200000.dwc3/xhci-hcd.2.auto/usb3/3-1’ found: /sys/devices/platform/soc@0/32f10108.usb/38200000.dwc3/xhci-hcd.2.auto/usb4/4-0:1.0/usb4-port1
[01 Jun 2023, 17:56:42] [Debug] [qfu-utils] couldn’t ping ModemManager: GDBus.Error:org.freedesktop.DBus.Error.NameHasNoOwner: Name “org.freedesktop.ModemManager1” does not exist
[01 Jun 2023, 17:56:42] [Debug] [qfu-image] loading file info…
[01 Jun 2023, 17:56:42] [Debug] [qfu-image] opening file for reading…
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] reading image headers…
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [0,34879232]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [400,426084]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [800,7680]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 800 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [7680,426084]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 7680 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 400 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [426084,26178380]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [426484,433404]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 426484 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [433404,672268]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 433404 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [672268,26178380]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 672268 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 426084 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [26178380,27381096]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [26178780,26185740]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 26178780 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [26185740,27121040]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 26185740 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27121040,27223952]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27121040 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27223952,27381096]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27223952 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 26178380 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27381096,27432883]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27381496,27388776]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27381896,27388776]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27381896 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27381496 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27388776,27431881]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27389176,27431881]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27389176 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27388776 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27431881,27432883]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27432281,27432883]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27432281 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27431881 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27381096 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27432883,34495475]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27433283,27440203]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27433283 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [27440203,34363963]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27440203 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [34363963,34495475]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 34363963 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 27432883 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [34495475,34879232]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [34495875,34503155]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [34496275,34503155]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 34496275 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 34495875 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [34503155,34879232]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image offset range: [34503555,34879232]
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 34503555 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 34503155 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] image at offset 34495475 is valid
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] validating data size…
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] preloading firmware/config/carrier…
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] firmware version: 00.08.24.02
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] config version: 001.110_000
[01 Jun 2023, 17:56:42] [Debug] [qfu-image-cwe] carrier: GENERIC
[01 Jun 2023, 17:56:42] [Debug] [qfu,device-selection] single tty device requested in sysfs path ‘/sys/devices/platform/soc@0/32f10108.usb/38200000.dwc3/xhci-hcd.2.auto/usb3/3-1’
[01 Jun 2023, 17:56:42] [Debug] [qfu,device-selection] device found: /dev/ttyUSB0
[01 Jun 2023, 17:56:42] [Debug] [qfu,device-selection] using preferred device: /dev/ttyUSB0
[01 Jun 2023, 17:56:42] [Debug] [qfu-sahara-device] opening TTY: /dev/ttyUSB0
[01 Jun 2023, 17:56:42] [Debug] [qfu-sahara-device] setting terminal in raw mode…
[01 Jun 2023, 17:56:42] [Debug] [qfu-sahara-device] waiting time for device to boot properly…
[01 Jun 2023, 17:56:44] [Debug] [qfu-sahara-device] initializing sahara protocol…
[01 Jun 2023, 17:56:47] [Debug] [qfu-updater] sahara device creation failed: no sahara response received
[01 Jun 2023, 17:56:47] [Debug] [qfu-qdl-device] opening TTY: /dev/ttyUSB0
[01 Jun 2023, 17:56:47] [Debug] [qfu-qdl-device] setting terminal in raw mode…
[01 Jun 2023, 17:56:47] [Debug] [qfu,dload-message] sent sdp:
[01 Jun 2023, 17:56:47] [Debug] [qfu-qdl-device] >> 70:00:00 [3, unframed]
[01 Jun 2023, 17:56:47] [Debug] [qfu-qdl-device] >> 7E:70:00:00:14:46:7E [7]
[01 Jun 2023, 17:56:47] [Debug] [qfu-qdl-device] << 01:00:00:00:30:00:00:00:02:00:00:00:01:00:00:00:00:04:00:00:02:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00 [48]
[01 Jun 2023, 17:56:47] [Debug] [qfu-updater] qdl device creation failed: HDLC trailing control character not found
error: unsupported download protocol
Seems very similar behaviour to the issue described in 28067
Is there an alternative method of downloadind the firmware once the device is in Download Mode?
May be a way to restore it to factory firmware?
Thank you!