avrdude on linux terminal

It seems that I’m missing a “-F” here.

What I sent
sudo avrdude -c usbasp -p m644p -U flash:w:firmware2.1.5.hex

what I’m supposed to send

sudo avrdude -c usbasp -p -F m644p -U flash:w:firmware2.1.5.hex

I suspected this since an answer was;

> Double check chip, or use -F to override this check.

Should I “force” the command ?

@ cuteboi I already wrote the lsusb outcome in my first post

From avrdude masnual

-F      Normally, avrdude tries to verify that the device signature
                   read from the part is reasonable before continuing.  Since
                   it can happen from time to time that a device has a broken
                   (erased or overwritten) device signature but is otherwise
                   operating normally, this options is provided to override
                   the check.  Also, for programmers like the Atmel STK500 and
                   STK600 which can adjust parameters local to the programming
                   tool (independent of an actual connection to a target con‐
                   troller), this option can be used together with -t to con‐
                   tinue in terminal mode.

@ray: infact the app is no longer showing the red alert on the upper right. But I’m baffled: the very same app insists on telling me that the firmware is still 2.0.9. (From information: app 1.4.5)
Which part of the app is trustable ?

I lean on the side of the old firmware: the old programs are still there without restoring them from the backup

Thanks Samer. I actually do not remember to have dismissed the notification: but evidently this was the case

I finally succeeded to upgrade to 2.1.5: the right command for OS 2.1 was

sudo avrdude -c usbasp -F -p m644 -U flash:w:firmware2.1.5.hex
which gave

avrdude: warning: cannot set sck period. please check for usbasp firmware update.
avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e9609
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: warning: cannot set sck period. please check for usbasp firmware update.
avrdude: reading input file "firmware2.1.5.hex"
avrdude: input file firmware2.1.5.hex auto detected as Intel Hex
avrdude: writing flash (56878 bytes):

Writing | ################################################## | 100% 3.97s

avrdude: 56878 bytes of flash written
avrdude: verifying flash memory against firmware2.1.5.hex:
avrdude: load data flash data from input file firmware2.1.5.hex:
avrdude: input file firmware2.1.5.hex auto detected as Intel Hex
avrdude: input file firmware2.1.5.hex contains 56878 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 2.71s

avrdude: verifying ...
avrdude: 56878 bytes of flash verified

avrdude: safemode: Fuses OK (H:00, E:00, L:00)
avrdude: error: usbasp_transmit: error sending control message: Protocol error

avrdude done.  Thank you.