immediate qcserial disconnect

[pswiatki]

I am trying to run qdl with my phone, which is in EDL mode. Just to be sure it really is in EDL:

2026-02-14T15:26:50.837639+01:00 sdr-aptv kernel: usb 3-12: new high-speed USB device number 29 using xhci_hcd
2026-02-14T15:26:50.962619+01:00 sdr-aptv kernel: usb 3-12: New USB device found, idVendor=05c6, idProduct=9008, bcdDevice= 0.00
2026-02-14T15:26:50.963127+01:00 sdr-aptv kernel: usb 3-12: New USB device strings: Mfr=1, Product=2, SerialNumber=0
2026-02-14T15:26:50.963379+01:00 sdr-aptv kernel: usb 3-12: Product: QUSB_BULK_CID:040E_SN:xxxxxxxxxxxx
2026-02-14T15:26:50.963640+01:00 sdr-aptv kernel: usb 3-12: Manufacturer: Qualcomm CDMA Technologies MSM
2026-02-14T15:26:50.965635+01:00 sdr-aptv kernel: qcserial 3-12:1.0: Qualcomm USB modem converter detected
2026-02-14T15:26:50.966136+01:00 sdr-aptv kernel: usb 3-12: Qualcomm USB modem converter now attached to ttyUSB0

Sadly, as soon as I issue:

[pswiatki@sdr-aptv images]$ sudo qdl --debug prog_ufs_firehose_sm6150_lite.elf rawprogram*.xml patch*.xml
qdl version unknown-version
USB: using out-chunk-size of 1048576
Sahara image id in read requests will be ignored
Sahara images:
   0: prog_ufs_firehose_sm6150_lite.elf
failed to read sahara request from device

At the same time, I get a disconnect message in journald:

2026-02-14T15:26:59.269568+01:00 sdr-aptv sudo[17135]: pswiatki : TTY=pts/2 ; PWD=/mnt/ext_home/pswiatki/devel/cell/xiaomi/mojito_global_images_V14.0.9.0.SKGMIXM_20240616.0000.00_12.0_global/images ; USER=root ; COMMAND=/usr/bin/qdl --debug prog_ufs_firehose_sm6150_lddr.elf rawprogram0.xml rawprogram1.xml rawprogram2.xml rawprogram3.xml rawprogram4.xml rawprogram5.xml patch0.xml patch1.xml patch2.xml patch3.xml patch4.xml patch5.xml
2026-02-14T15:26:59.270991+01:00 sdr-aptv sudo[17135]: pam_unix(sudo:session): session opened for user root(uid=0) by pswiatki(uid=1000)
2026-02-14T15:26:59.301542+01:00 sdr-aptv kernel: qcserial ttyUSB0: Qualcomm USB modem converter now disconnected from ttyUSB0
2026-02-14T15:26:59.301766+01:00 sdr-aptv kernel: qcserial 3-12:1.0: device disconnected
2026-02-14T15:27:00.302667+01:00 sdr-aptv sudo[17135]: pam_unix(sudo:session): session closed for user root

Question: why is that?