[pulseaudio-discuss] [PATCH] loopback: Fix crash if Max Request change at unload

David Henningsson david.henningsson at canonical.com
Wed Mar 21 00:04:48 PDT 2012

On 03/20/2012 06:10 PM, Dalleau, Frederic wrote:
> Hi David,
> On Tue, Mar 20, 2012 at 4:06 PM, David Henningsson
> <david.henningsson at canonical.com>  wrote:
>> On 02/10/2012 05:39 PM, Frédéric Dalleau wrote:
>>> Module-bluetooth-policy can load and unload module-loopback on demand.
>>> Sometimes if there is an error, module-loopback can be unloaded early.
>>> When module-loopback is loaded, it attaches a sink and the sink
>>> calls sink_input_update_max_request for which there is a callback.
>> Hmm, I saw this as well and committed a patch for it today (before I checked
>> this post unfortunately!)
>> Would you mind reviewing my patch "Never call adjust_rates after teardown"
>> to see if it affects/resolves your problem as well?
> I'm in the middle of something, I hope I can look at your patch within
> a day or two.
>  From reading the code, I think it could reduce bug frequency.
> Have you reproduced the crash yourself?

No, I just saw the crash report on launchpad and tried to figure out the 
likely cause for it. The person in question had combined 
module-null-sink with module-loopback and got a segfault from 
sink_input_update_max_request calling adjust_rates with a null u->source.

For reference, the stack trace is here:


David Henningsson, Canonical Ltd.

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