On Thu, Mar 18, 2010 at 04:43:06PM +0000, Mark Brown wrote: > On Thu, Mar 18, 2010 at 05:17:55PM +0100, Daniel Mack wrote: > > > So the first stream (PLAYBACK) already exported its dma_data which is > > now freed by the code initializing the second stream (CAPTURE). > > This corrupts all existing users of course, and in this particular case, > > the cleanup in __pxa2xx_pcm_hw_free() dereferences a pointer which is > > bogus. > > > What I really don't understand is why this didn't crash a lot earlier > > for many more users. > > > So how is this supposed to be fixed? Should dma_data become a member of > > some per-stream instance? I believe that also other platforms than PXA > > are actually affected - am I right? > > It should really be per-substream, yes. Do you want me to fix this or are you working on this already? I know there are some pxa-ssp related things pending which will also cause merge conflicts - which tree should thing apply to currently? > It's relatively hard to trigger problems on a lot of platform since the > DAI data pointer is often only really used at stream setup, meaning that > triggering a problem requires that a system not only does simultaneous > playback and capture but also has overlapping startup of the two. Well, how would you initialize them in a non-overlapping way? The example I sent does the setup fairly straight-forward, doesn't it? I'd say any full-duplex system is affected. Daniel _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
