Make the RPM partition read-only. This was a mistake and a leftover from
staging branch but I can take this mistake as an excuse to document the
current problem with RPM.
It might happen that a board ship with a broken RPM .mbn, broken not in
the sense that the board doesn't boot or it's a brick but broken in the
sense that it's outdaed and suffer from a bug fixed in new version.
This bug consist in a problem with the regulators between USB and NSS.
The old RPM mess with the NSS regulator (l2) and change the voltage for
it while configuring the USB regulator (l5).
This cause the ethernet subsystem to malfunction with the port not
working.
To workaround this, it's needed to disable RPM handling and CPUFreq.
With these 2 disabled, the old RPM doesn't touch regulators and Ethernet
works correctly.
New RPM correctly handle regulators for USB (l5) and doesn't suffer from
this problem. A solution for this is getting discussed with QCOM hoping
to get some good feedback for it.
Link: https://github.com/openwrt/openwrt/pull/17788
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
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