On Mon, Sep 12, 2016 at 06:28:56PM +0200, Takashi Iwai wrote: > On Mon, 12 Sep 2016 18:03:16 +0200, > Charles Keepax wrote: > > > > On Mon, Sep 12, 2016 at 05:28:58PM +0200, Takashi Iwai wrote: > > > On Mon, 12 Sep 2016 17:25:31 +0200, > > > Vinod Koul wrote: > > > > > > > > On Mon, Sep 12, 2016 at 01:37:37PM +0100, Charles Keepax wrote: > > > > > On Tue, Sep 06, 2016 at 12:30:35PM +0900, Takashi Sakamoto wrote: > > > Also, still another point is to be decided: is passing an arbitrary > > > size via info callback for an element without read/write access bits > > > (but with TLV bit) a right behavior? > > > > > > > So I guess the question would be if you couldn't read the > > controls size from info how would you find out the control size? > > Well, I'm not against the idea to expose the size in callback. The > behavior without read/write bits is just undefined, and we need a > clear definition to avoid further confusion. I guess the introduction > of a new flag would be the start. The trouble with that is you have to do a read/write to find out the size you need to read or write though. So you end up doing weird stuff like a dummy zero length read or something, which feels a bit icky. One other thing to consider is that if we add the new flag it might be nice to allow normal read/write operations on the controls as well (only accessing the first 512 bytes of the control). Certainly for the ADSP control I would have liked to have done this to preserve better backwards compatibility with older user-spaces. Thanks, Charles _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
