From: Jack Stone <jwjstone@fastmail.fm>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alan Stern <stern@rowland.harvard.edu>,
Oliver Neukum <oliver@neukum.org>,
Matthew Garrett <mjg@redhat.com>, Dave Jones <davej@redhat.com>,
Linux Kernel <linux-kernel@vger.kernel.org>,
Larry Finger <Larry.Finger@lwfinger.net>,
Chaoming Li <chaoming_li@realsil.com.cn>,
"John W. Linville" <linville@tuxdriver.com>,
Greg Kroah-Hartman <gregkh@suse.de>,
USB list <linux-usb@vger.kernel.org>,
Linux Wireless List <linux-wireless@vger.kernel.org>
Subject: Re: loading firmware while usermodehelper disabled.
Date: Mon, 02 Jan 2012 20:55:07 +0000 [thread overview]
Message-ID: <4F0219AB.6010505@fastmail.fm> (raw)
In-Reply-To: <CA+55aFwf06vRraVqtz8_2qWjxH0V=Yj5m7mEy3XVbA7+qj5k5A@mail.gmail.com>
On 02/01/12 20:48, Linus Torvalds wrote:
> On Mon, Jan 2, 2012 at 12:41 PM, Jack Stone <jwjstone@fastmail.fm> wrote:
>>
>> What about the case where the firmware that needs to be loaded is on the
>> USB device that needs the firmware. This can be resolved at boot using
>> an initrd but at resume time we don't have that.
>
> Quite frankly, caching the firmware will just automagically fix this.
>
> I don't understand why people even bother to talk about USB ID's etc
> changing - that is totally irrelevant. We don't look up firmware by
> USB ID's anyway.
I agree. The only problem I can see is with the lifetime of the
firmware. If we have a generic USB driver that looks after (for example)
all USB disks then we do not want to add the knowedge to it for each
individual vendors firmware.
For example:
1/ Plug in device, registers as a bootstrap device
2/ Load firmware into device (and put firmware in cache)
3/ Device disconnects and reconnects with new USB id
4/ Generic driver takes over as it recognizes the new id
The problem comes with knowing when to put the firmware - how do we tell
the generic driver that that device has firmware that might need to be
freed on disconnect. I don't know enough about USB to know if we can
tell if the same device has reconnected due to firmware being loaded or
if it was simply unplugged and a new device plugged in.
Hope this makes sense,
Jack
next prev parent reply other threads:[~2012-01-02 20:55 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20111230235421.GA6054@redhat.com>
2011-12-31 0:22 ` loading firmware while usermodehelper disabled 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 [this message]
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 9:24 ` 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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