On Wed, Jan 17, 2018 at 08:38:48PM +0100, Maciej S. Szmigiero wrote: > However, I have a small nitpick regarding a comment newly added in > this version of patch 16: > + /* > + * Do not set SSI dev as the parent of AC97 CODEC device since > + * it does not have a DT node. Otherwise ASoC core will assume > + * CODEC has the same DT node as the SSI, so it may return a > + * NULL pointer of CODEC when asked for SSI via the DT node > > The second part of the last sentence isn't really true, the ASoC core > will return a (valid, non-NULL) CODEC object pointer when asked for > the SSI one if we set the SSI as the parent device of a AC'97 CODEC > platform device. > > The NULL pointer dereference when starting a playback that I wrote > about in my previous message happens because in this situation the SSI > DAI probe callback won't ever get called and so won't setup DMA data > pointers (they will remain NULL). Well, somehow the DMA data pointer of CODEC could be described as "a NULL pointer of CODEC" reluctantly...it confuses people though. > And this in turn will cause the ASoC DMA code to dereference these > NULL pointers when starting a playback (the same will probably happen > also when starting a capture). > > Sorry if I wasn't 100% clear about these details in my previous > message describing this issue. I would prefer to send an incremental patch later to update it, if there are no new comments against this version; Otherwise, I will update it in a next version once there is a need to send a v6 anyway. Thanks _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
