[Bug 204807] Hardware monitoring sensor nct6798d doesn't work unless acpi_enforce_resources=lax is enabled

bugzilla-daemon
2021-04-15T09:39:51Z

--- Comment #69 from Hans de Goede (jwrdegoede@fedoraproject.org) ---
(In reply to Artem S. Tashkinov from comment #67)
> Multiple users use acpi_enforce_resources=lax and I haven't seen a single
> report that it's ever broken anything.

<sigh> Yet I have been on the receiving end of a bug-report where I had to
explain to a user that the lm_sensors sensors-detect script had overvolted his
RAM ruining both his expensive high-end RAM as well as his expensive top of the
line CPU. The user was surprisingly relaxed about all this, which I really
appreciated.

And that was while the script was not doing anything which we (the developers)
considered dangerous. But the motherboard had a funky setup causing a SMbus
*read* transaction to change the voltage.

Mucking with this stuff can be dangerous and as Matthew has explained in his
thorough analysis of the DSDT the DSDT is actually accessing the superio and if
that races with a Linux kernel access a wrong register may be read from, or
worse written to.

Using acpi_enforce_resources=lax simply is dangerous and we are not going to
change the default, period, full-stop.

I welcome further discussions here about how we can *safely* solve hwmon access
on various motherboards.

Please stop discussing acpi_enforce_resources=lax, that is not a safe option to
use and more discussion about it is not productive.