Fwd: [Bug 827538] DVB USB device firmware requested in module_init()

Fwd: [Bug 827538] DVB USB device firmware requested in module_init()

[Antti Palosaari]

-------- Original Message --------
Subject: [Bug 827538] DVB USB device firmware requested in module_init()
Date: Fri, 01 Jun 2012 19:44:17 +0000
From: bugzilla@redhat.com
To: crope@iki.fi

https://bugzilla.redhat.com/show_bug.cgi?id=827538

Kay Sievers <kay@redhat.com> changed:

            What    |Removed                     |Added
----------------------------------------------------------------------------
                  CC|                            |gansalmon@Gmail.com,
                    |                            |itamar@ispbrasil.com.br,
                    |                            |kernel-maint@redhat.com,
                    |                            |madhu.chinakonda@gmail.com
           Component|udev                        |kernel
            Assignee|udev-maint@redhat.com       |kernel-maint@redhat.com
             Summary|DVB USB device firmware     |DVB USB device firmware
                    |downloading takes 30        |requested in module_init()
                    |seconds                     |

--- Comment #1 from Kay Sievers <kay@redhat.com> ---
This is very likely a kernel driver issue.

Drivers must not load firmware in the module_init() path, or device
probe()/bind() path. This creates a deadlock in the event handling.

We used to silently try to work around that, but recently started
to log this error explicitely.

The firmware should in general be requested asynchronously, or at the first
open() of the device.

Details are here:
   http://thread.gmane.org/gmane.linux.network/217729

-- 
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Re: Fwd: [Bug 827538] DVB USB device firmware requested in module_init()

[Antti Palosaari]

On 06/01/2012 10:52 PM, Antti Palosaari wrote:
>
>
> -------- Original Message --------
> Subject: [Bug 827538] DVB USB device firmware requested in module_init()
> Date: Fri, 01 Jun 2012 19:44:17 +0000
> From: bugzilla@redhat.com
> To: crope@iki.fi
>
> https://bugzilla.redhat.com/show_bug.cgi?id=827538
>
> Kay Sievers <kay@redhat.com> changed:
>
> What |Removed |Added
> ----------------------------------------------------------------------------
>
> CC| |gansalmon@Gmail.com,
> | |itamar@ispbrasil.com.br,
> | |kernel-maint@redhat.com,
> | |madhu.chinakonda@gmail.com
> Component|udev |kernel
> Assignee|udev-maint@redhat.com |kernel-maint@redhat.com
> Summary|DVB USB device firmware |DVB USB device firmware
> |downloading takes 30 |requested in module_init()
> |seconds |
>
> --- Comment #1 from Kay Sievers <kay@redhat.com> ---
> This is very likely a kernel driver issue.
>
> Drivers must not load firmware in the module_init() path, or device
> probe()/bind() path. This creates a deadlock in the event handling.
>
> We used to silently try to work around that, but recently started
> to log this error explicitely.
>
> The firmware should in general be requested asynchronously, or at the first
> open() of the device.
>
> Details are here:
> http://thread.gmane.org/gmane.linux.network/217729
>

I suspect all of our DVB USB firmere downloading problems are coming 
from that issues. I mean especially those suspend / resume failings too.

What I think I will try to delay driver registertration using workqueue. 
Return just success for the USB driver probe and continue real probe 
from workqueue.

Antti
-- 
http://palosaari.fi/

Re: Fwd: [Bug 827538] DVB USB device firmware requested in module_init()

[Antti Palosaari]

On 06/02/2012 07:39 PM, Antti Palosaari wrote:
> On 06/01/2012 10:52 PM, Antti Palosaari wrote:
>>
>>
>> -------- Original Message --------
>> Subject: [Bug 827538] DVB USB device firmware requested in module_init()
>> Date: Fri, 01 Jun 2012 19:44:17 +0000
>> From: bugzilla@redhat.com
>> To: crope@iki.fi
>>
>> https://bugzilla.redhat.com/show_bug.cgi?id=827538
>>
>> Kay Sievers <kay@redhat.com> changed:
>>
>> What |Removed |Added
>> ----------------------------------------------------------------------------
>>
>>
>> CC| |gansalmon@Gmail.com,
>> | |itamar@ispbrasil.com.br,
>> | |kernel-maint@redhat.com,
>> | |madhu.chinakonda@gmail.com
>> Component|udev |kernel
>> Assignee|udev-maint@redhat.com |kernel-maint@redhat.com
>> Summary|DVB USB device firmware |DVB USB device firmware
>> |downloading takes 30 |requested in module_init()
>> |seconds |
>>
>> --- Comment #1 from Kay Sievers <kay@redhat.com> ---
>> This is very likely a kernel driver issue.
>>
>> Drivers must not load firmware in the module_init() path, or device
>> probe()/bind() path. This creates a deadlock in the event handling.
>>
>> We used to silently try to work around that, but recently started
>> to log this error explicitely.
>>
>> The firmware should in general be requested asynchronously, or at the
>> first
>> open() of the device.
>>
>> Details are here:
>> http://thread.gmane.org/gmane.linux.network/217729
>>
>
> I suspect all of our DVB USB firmere downloading problems are coming
> from that issues. I mean especially those suspend / resume failings too.
>
> What I think I will try to delay driver registertration using workqueue.
> Return just success for the USB driver probe and continue real probe
> from workqueue.

That solves DVB USB firmware loading problems. I wonder why that udev 
requirement not to block module init was not informed for linux-media... 
Now it is much work to look thru all drivers and check those did not 
load firmware on attach or init.

regards
Antti
-- 
http://palosaari.fi/

Re: Fwd: [Bug 827538] DVB USB device firmware requested in module_init()

[Brian J. Murrell]

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On 12-06-02 10:44 PM, Antti Palosaari wrote:
> 
> That solves DVB USB firmware loading problems.

As in you have a patch that works or it's just solved "in theory".  If
you have a patch I'd love to apply it here and get this machine
suspendable again.

Cheers,
b.


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Re: Fwd: [Bug 827538] DVB USB device firmware requested in module_init()

[Antti Palosaari]

On 06/03/2012 05:38 PM, Brian J. Murrell wrote:
> On 12-06-02 10:44 PM, Antti Palosaari wrote:
>>
>> That solves DVB USB firmware loading problems.
>
> As in you have a patch that works or it's just solved "in theory".  If
> you have a patch I'd love to apply it here and get this machine
> suspendable again.

I have patch which works but is as a proof-of-concept stage. I am just 
finalizing it. I will inform when it is ready, likely later tonight (as 
I would like to really see it fixes that suspend/resume problem as I am 
not able to reproduce it for some reason).

regards
Antit
-- 
http://palosaari.fi/

Re: Fwd: [Bug 827538] DVB USB device firmware requested in module_init()

[Antti Palosaari]

On 06/03/2012 05:43 PM, Antti Palosaari wrote:
> On 06/03/2012 05:38 PM, Brian J. Murrell wrote:
>> On 12-06-02 10:44 PM, Antti Palosaari wrote:
>>>
>>> That solves DVB USB firmware loading problems.
>>
>> As in you have a patch that works or it's just solved "in theory". If
>> you have a patch I'd love to apply it here and get this machine
>> suspendable again.
>
> I have patch which works but is as a proof-of-concept stage. I am just
> finalizing it. I will inform when it is ready, likely later tonight (as
> I would like to really see it fixes that suspend/resume problem as I am
> not able to reproduce it for some reason).

That firmware downloading patch is done top of my new dvb-usb 
development tree. I have converted very limited set of drivers for that 
tree, af9015, au6610, ec168 and anysee (and those are only on my local 
hard disk). I tried to backport patch for the current dvb-usb but I ran 
many problems and gave up. Looks like it is almost impossible to convert 
old dvb-usb without big changes...

So what driver you are using? It is possible I can convert your driver 
too and then it is possible to test.

Patch in question can be found from that tree:
http://git.linuxtv.org/anttip/media_tree.git/shortlog/refs/heads/dvb-usb

regards
Antti
-- 
http://palosaari.fi/

Re: Fwd: [Bug 827538] DVB USB device firmware requested in module_init()

[Brian J. Murrell]

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On 12-06-03 05:01 PM, Antti Palosaari wrote:
> 
> That firmware downloading patch is done top of my new dvb-usb
> development tree. I have converted very limited set of drivers for that
> tree, af9015, au6610, ec168 and anysee (and those are only on my local
> hard disk). I tried to backport patch for the current dvb-usb but I ran
> many problems and gave up. Looks like it is almost impossible to convert
> old dvb-usb without big changes...
> 
> So what driver you are using?

I'm using the hvr-950q per
https://bugzilla.kernel.org/show_bug.cgi?id=43145 and
https://bugzilla.kernel.org/show_bug.cgi?id=43146.

> It is possible I can convert your driver
> too and then it is possible to test.

Great.  Ideally it would be great to get this backported and applied to
the linux 3.2.0 release stream.

Cheers,
b.



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Re: Fwd: [Bug 827538] DVB USB device firmware requested in module_init()

[Devin Heitmueller]

On Mon, Jun 4, 2012 at 9:32 AM, Brian J. Murrell <brian@interlinx.bc.ca> wrote:
> On 12-06-03 05:01 PM, Antti Palosaari wrote:
>>
>> That firmware downloading patch is done top of my new dvb-usb
>> development tree. I have converted very limited set of drivers for that
>> tree, af9015, au6610, ec168 and anysee (and those are only on my local
>> hard disk). I tried to backport patch for the current dvb-usb but I ran
>> many problems and gave up. Looks like it is almost impossible to convert
>> old dvb-usb without big changes...
>>
>> So what driver you are using?
>
> I'm using the hvr-950q per
> https://bugzilla.kernel.org/show_bug.cgi?id=43145 and
> https://bugzilla.kernel.org/show_bug.cgi?id=43146.
>
>> It is possible I can convert your driver
>> too and then it is possible to test.
>
> Great.  Ideally it would be great to get this backported and applied to
> the linux 3.2.0 release stream.

The 950q doesn't use the dvb-usb framework (nor does it load the
firmware at init).  Whatever is going on there is completely unrelated
to what Antti is debugging.

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com

Re: Fwd: [Bug 827538] DVB USB device firmware requested in module_init()

[Brian J. Murrell]

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On 12-06-04 09:35 AM, Devin Heitmueller wrote:
> 
> The 950q doesn't use the dvb-usb framework (nor does it load the
> firmware at init).  Whatever is going on there is completely unrelated
> to what Antti is debugging.

Ahhh.  Pity.  I was almost giddy there for a second.  :-/

Cheers,
b.



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