From: Matthew Garrett <mjg@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: drahemmaps@gmx.net, davej@redhat.com,
linux-kernel@vger.kernel.org, gregkh@suse.de,
linux-usb@vger.kernel.org
Subject: Re: loading firmware while usermodehelper disabled.
Date: Sat, 31 Dec 2011 20:15:39 +0000 [thread overview]
Message-ID: <20111231201538.GA29758@srcf.ucam.org> (raw)
In-Reply-To: <CA+55aFyFuKVgzuOuszb+UyCh98R2TZ_QiS0TCWJjJX5zEwLSWw@mail.gmail.com>
On Sat, Dec 31, 2011 at 11:29:56AM -0800, Linus Torvalds wrote:
> But what the driver *should* be doing is to load the firmware at
> device open time (NOT at "driver load time" - because that can and
> does happen too early too, for the case of built-in drivers!) and
> simply keep the firmware around in the case of a suspend/resume event,
> so that it doesn't have to re-load it off a disk (or network, or
> whatever) that hasn't been resumed yet!
That doesn't work for the isight firmware loader - there's nothing for
userspace to open until the device has had the firmware loaded, at which
point it detaches and reattaches as a UVC device. The code could be
merged into the UVC driver and a fake v4l device exposed, but even then
you'd still need to deal with the underlying usb_device suddenly
changing under you.
So for this specific case, I'd like to track down why the behaviour has
changed - if the device was previously maintaining state over suspend
and now isn't then that's something that's broken, but if it's just that
some ordering has changed and now it's losing a race, I'll need to fix
it in the driver. One option would be to do away with the kernelspace
loader entirely and push it out to a udev helper, or alternatively just
have the driver stash the firmware all the time.
--
Matthew Garrett | mjg59@srcf.ucam.org
next prev parent reply other threads:[~2011-12-31 20:15 UTC|newest]
Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-31 15:01 loading firmware while usermodehelper disabled drahemmaps
2011-12-31 19:29 ` Linus Torvalds
2011-12-31 20:15 ` Matthew Garrett [this message]
2011-12-31 20:26 ` Linus Torvalds
-- strict thread matches above, loose matches on Subject: below --
2011-12-30 23:54 Dave Jones
2011-12-31 0:22 ` Linus Torvalds
2011-12-31 0:40 ` Matthew Garrett
2011-12-31 15:33 ` Alan Stern
2011-12-31 15:59 ` Oliver Neukum
2012-01-01 2:21 ` Alan Stern
2012-01-01 12:22 ` Oliver Neukum
2012-01-01 16:17 ` Alan Stern
2012-01-01 16:25 ` Michael Büsch
2012-01-01 20:30 ` Linus Torvalds
2012-01-01 21:27 ` Oliver Neukum
2012-01-01 21:39 ` Michael Büsch
2012-01-02 3:33 ` Matthew Garrett
2012-01-02 7:56 ` Oliver Neukum
2012-01-02 4:17 ` Marek Vasut
2012-01-02 5:35 ` Gábor Stefanik
2012-01-02 8:38 ` Marek Vasut
2012-01-02 16:54 ` Alan Stern
2012-01-02 20:41 ` Jack Stone
2012-01-02 20:48 ` Linus Torvalds
2012-01-02 20:55 ` Jack Stone
2012-01-02 21:00 ` Linus Torvalds
2012-01-02 21:09 ` Jack Stone
2012-01-02 21:23 ` Linus Torvalds
2012-01-02 21:31 ` Jack Stone
2012-01-02 21:52 ` Marek Vasut
2012-01-02 21:57 ` Jack Stone
2012-01-02 22:31 ` Marek Vasut
2012-01-02 23:25 ` Jack Stone
2012-01-03 0:31 ` Marek Vasut
2012-01-03 0:44 ` Jack Stone
2012-01-03 0:58 ` Alan Cox
2012-01-03 7:17 ` Marek Vasut
2012-01-03 7:41 ` Oliver Neukum
2012-01-03 0:35 ` Alan Cox
2012-01-03 0:50 ` Alan Cox
2012-01-02 21:19 ` Matthew Garrett
2012-01-02 21:26 ` Jack Stone
2012-01-03 0:42 ` Alan Cox
2012-01-03 11:57 ` Oliver Neukum
2012-01-03 12:19 ` Jack Stone
2012-01-03 13:20 ` Alan Cox
2012-01-03 13:30 ` Oliver Neukum
2012-01-03 13:36 ` Alan Cox
2012-01-02 21:27 ` Linus Torvalds
2012-01-02 21:50 ` Matthew Garrett
2012-01-02 22:03 ` Linus Torvalds
2012-01-02 22:12 ` Matthew Garrett
2012-01-02 22:19 ` Linus Torvalds
2012-01-02 22:29 ` Matthew Garrett
2012-01-02 22:46 ` Linus Torvalds
2012-01-02 23:00 ` Matthew Garrett
2012-01-02 23:31 ` Jack Stone
2012-01-03 0:13 ` Matthew Garrett
2012-01-03 0:20 ` Alan Cox
2012-01-03 0:37 ` Matthew Garrett
2012-01-03 0:22 ` Jack Stone
2012-01-03 0:31 ` Alan Cox
2012-01-03 0:41 ` Jack Stone
2012-01-03 0:38 ` Matthew Garrett
2012-01-03 0:47 ` Alan Cox
2012-01-03 0:18 ` Alan Cox
2012-01-03 8:26 ` Ingo Molnar
2012-01-03 2:45 ` Alan Stern
2012-01-03 3:25 ` Matthew Garrett
2012-01-03 5:53 ` Linus Torvalds
2012-01-03 11:50 ` Oliver Neukum
2012-01-03 15:16 ` Alan Stern
2012-01-03 12:24 ` Matthew Garrett
2012-01-03 16:29 ` Linus Torvalds
2012-01-03 15:09 ` Alan Stern
2012-01-03 9:16 ` Alexander E. Patrakov
2012-01-03 9:16 ` Alexander E. Patrakov
2012-01-03 9:24 ` david
2012-01-03 13:43 ` Alan Cox
2012-01-03 14:12 ` Bernd Petrovitsch
2012-01-03 0:00 ` Alan Cox
2012-01-02 23:50 ` Alan Cox
2012-01-02 23:53 ` Alan Cox
2011-12-31 16:27 ` Matthew Garrett
2011-12-31 14:20 ` Martin Schleier
2011-12-31 18:39 ` Marek Vasut
2012-01-01 9:48 ` Oliver Neukum
2012-01-01 9:54 ` Marek Vasut
2012-01-01 12:28 ` Oliver Neukum
2012-01-01 16:32 ` Marek Vasut
2012-01-01 17:06 ` Marek Vasut
2012-01-01 20:39 ` Alan Cox
2012-01-01 20:50 ` Michael Büsch
2012-01-02 3:24 ` Marek Vasut
2012-01-02 3:29 ` Marek Vasut
2012-01-01 3:49 ` Larry Finger
2012-01-01 22:45 ` Jack Stone
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