linux-kernel - Re: [systemd-devel] [PATCH] Change CONFIG_FW_LOADER_USER

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Message-ID: <CALCETrX7aGpLAferwTbS3wQWwyw_v_DHh6se6c76fpfi6tJu=A@mail.gmail.com>
Date:	Tue, 6 Aug 2013 09:08:29 -0700
From:	Andy Lutomirski <luto@...capital.net>
To:	Tom Gundersen <teg@...m.no>
Cc:	Maarten Lankhorst <m.b.lankhorst@...il.com>,
	systemd-devel@...ts.freedesktop.org, linux-hotplug@...r.kernel.org,
	Linux Wireless List <linux-wireless@...r.kernel.org>,
	linux-kernel@...r.kernel.org,
	Intel Linux Wireless <ilw@...ux.intel.com>,
	Kay Sievers <kay@...y.org>,
	Johannes Berg <johannes@...solutions.net>
Subject: Re: [systemd-devel] [PATCH] Change CONFIG_FW_LOADER_USER_HELPER to
 default n and don't select it

On Tue, Aug 6, 2013 at 2:17 AM, Tom Gundersen <teg@...m.no> wrote:
> On Tue, Aug 6, 2013 at 11:11 AM, Tom Gundersen <teg@...m.no> wrote:
>> On Tue, Aug 6, 2013 at 10:20 AM, Maarten Lankhorst
>> <m.b.lankhorst@...il.com> wrote:
>>> Op 05-08-13 18:29, Andy Lutomirski schreef:
>>>> The systemd commit below can delay firmware loading by multiple
>>>> minutes if CONFIG_FW_LOADER_USER_HELPER=y.  Unfortunately no one
>>>> noticed that the systemd-udev change would break new kernels as well
>>>> as old kernels.
>>>>
>>>> Since the kernel apparently can't count on reasonable userspace
>>>> support, turn this thing off by default.
>>>>
>>>> commit a3bd8447be4ea2ce230eb8ae0e815c04d85fa15a
>>>> Author: Tom Gundersen <teg@...m.no>
>>>> Date:   Mon Mar 18 15:12:18 2013 +0100
>>>>
>>>>     udev: make firmware loading optional and disable by default
>>>>
>>>>     Distros that whish to support old kernels should set
>>>>       --with-firmware-dirs="/usr/lib/firmware/updates:/usr/lib/firmware"
>>>>     to retain the old behaviour.
>>>>
>>> methinks this patch should be reverted then,
>>
>> Well, all the code is still there, so it can be enabled if anyone wants it.
>>
>>> or a stub should be added to udev to always fail firmware loading so timeouts don't occur.
>>
>> I think the only use (if any) of a userspace firmware loader would be
>> for anyone who wants a custom one (i.e., not udev), so we shouldn't
>> just fail the loading from udev unconditionally.
>>
>> How about we just improve the udev documentation a bit, similar to
>> Andy's kernel patch?
>
> Sorry, I should first have checked. We already document this in the README:
>
>>        Userspace firmware loading is deprecated, will go away, and
>>        sometimes causes problems:
>>          CONFIG_FW_LOADER_USER_HELPER=n

TBH, the udev README is the last thing I'm going to check to figure
out why I don't have wifi for a couple minutes after boot.  Also, the
message is missing the point.  It's not that it's deprecated and
sometimes causes problems -- it's that udev *changed behavior* and
breaks your system if you have CONFIG_FW_LOADER_USER_HELPER=y.

If udev logged something (for a couple of years), that would be a
different story.

--Andy
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