On 17.01.2018 21:02, Nicolin Chen wrote: > 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. IMHO it is such a tiny thing that it isn't worth respinning 17 patch series just for it, it can be easily improved later via a separate patch. > Thanks > Thanks, Maciej _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
