Re: After upgrading to 4.11.1, wifi driver refuses to load after being unloaded once.

[Kalle Valo <kvalo@codeaurora.org>]

Luca Coelho <luca@coelho.fi> writes:

> On Wed, 2017-10-18 at 07:59 +0300, Kalle Valo wrote:
>> Luca Coelho <luca@coelho.fi> writes:
>> 
>> > On Tue, 2017-10-17 at 14:23 -0700, Marc MERLIN wrote:
>> >
>> > > I don't know how or why, but I seem to:
>> > > saruman:~# grep IWLWIFI /boot/config-4.12.10-amd64-preempt-sysrq-
>> > > 20170406 
>> > > CONFIG_IWLWIFI=m
>> > > CONFIG_IWLWIFI_LEDS=y
>> > > CONFIG_IWLWIFI_OPMODE_MODULAR=y
>> > > # CONFIG_IWLWIFI_BCAST_FILTERING is not set
>> > > CONFIG_IWLWIFI_PCIE_RTPM=y
>> > > CONFIG_IWLWIFI_DEBUG=y
>> > > CONFIG_IWLWIFI_DEVICE_TRACING=y
>> > > 
>> > > I'll remove that, thanks.
>> > 
>> > Cool, I think that might help.  If it doesn't, please report a bug
>> > in
>> > buzilla. ;)
>> 
>> But a Kconfig option should never break functionality, so IMHO this
>> still sounds like a bug in iwlwifi.
>
> The problem is that to get this to work, some changes need to be made
> in the platform side.  In this case, the rootport is not configured
> properly so it won't work.

Yeah, but users or distros might accidentally enable this Kconfig
option and break the driver unintentionally. And subtle bugs like this
are even worse as the user will not realise that it's because of a new
Kconfig option.

So I guess you can't automatically detect it the platform supports RTPM,
right? Maybe there should be a module parameter which has to be set to
enable this? And at least a big fat warning to the user that RTPM is
enabled, bugs are likely and the user has to know what she's doing.

> We discussed this before and that's why this option now depends on
> EXPERT.

Heh, we did? I have no recollection of whatsoever about that :)

-- 
Kalle Valo