Messages in this thread | | | Date | Wed, 14 Jan 2015 12:02:28 +0000 | From | Mark Brown <> | Subject | Re: [alsa-devel] unload Audio drivers while playback stream is active case kernel crash |
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On Wed, Jan 14, 2015 at 11:50:48AM +0100, Takashi Iwai wrote: > Lars-Peter Clausen wrote:
> > > OK, so it's not about active stream. From the reporter's description, > > > I supposed that the module gets unloaded while playing a stream, which > > > shouldn't be allowed.
> > Well one of the ways to trigger this is to remove the module while the > > stream is active. But it is not exclusively a problem module unload problem. > > E.g. the same happens if you hot-unplug the ASoC card.
> Yes, unbinding can trigger a similar problem, ends up the same bad > code path.
Right, which was my point - we need to be able to cope with the driver being removed while in use, unbind is just one path where this could happen and the issue isn't specific to unbind.
> > I don't think that we need to prevent module unload when a stream is active. > > From a framework point of view is not different from hot-unplug. I don't > > see a reason why we'd jump through hoops to actively forbid removing the > > module once it works just fine.
> Well, the module unload means a more drastic cleanup. Even if you > unbind, the code and data are still there while module unload may > clean them up all.
> Above all, disallowing the module unload while using is the common > behavior of any other drivers. Why do we have to be a rebel against > all civil manner? :)
That's not true for everything and for ASoC I'd tend to assume that the user knows what they're doing and has a good reason for it; it's certainly something that can be helpful in development. [unhandled content-type:application/pgp-signature] | |