Usability issues for DSA upgrade

[Luiz Angelo Daros de Luca]

Hello,

While upgrading from 19.07 to 21.02, there is an scary error message
when target migrates to DSA (both Luci or CLI):

root at OpenWrt:/tmp# sysupgrade -n
openwrt-21.02.0-rc3-mvebu-cortexa9-linksys_wrt1900acs-squashfs-sysupgrade.bin
Device linksys,shelby not supported by this image
Supported devices: linksys,wrt1900acs armada-385-linksys-shelby
linksys,shelby - Image version mismatch: image 1.1, device 1.0. Please
wipe config during upgrade (force required) or reinstall. Reason:
Config cannot be migrated from swconfig to DSA
Image check failed.

OpenWrt devs are probably confident that they can force an upgrade for
that image. "force" means "I know what I'm doing, ignore the checks".
However, for many users, sometimes non-technical ones, they do not
really know what they are doing. There might be a wave of support
requests about that message and another wave of bricked devices. Even
knowing some OpenWrt internals, I'm not sure what "...or reinstall"
means. Shouldn't '-n' be enough? Isn't sysupgrade already a reinstall?
Or should it be the factory image? If it is really suggesting factory
images, should I return to the original firmware before or use some
emergency firmware recovery?

Can we provide a 19.07 update to, at least, allow the upgrade without
errors or "force" if confs are not kept? "Force" comes with great
responsibility and it will overwrite other checks as board
compatibility.

The error message could be, instead of:

"Please wipe config during upgrade (force required) or reinstall.
Reason: Config cannot be migrated from swconfig to DSA"

Something like this:

"Configuration cannot be migrated from swconfig to DSA. To properly
validate this firmware, please update OpenWrt at least to version
19.07.8 or pkgfoobar to version 1.2.3 and retry. Alternatively, if you
are sure that this image is compatible, you can proceed not retaining
the current configuration and forcing the process."

I omitted the "...or reinstall'' as I'm still not sure what it means.
I also used "not retaining the current configuration" as Luci (nor
sysupgrade) does not mention wipe but "Keep settings and retain the
current configuration" (which, by the way, seems to be two redundant
sentences).

Regards,

---
     Luiz Angelo Daros de Luca
            luizluca at gmail.com