On Fri, 02 Feb 2018 10:57:28 +0100, Dan Carpenter wrote: > > On Fri, Feb 02, 2018 at 06:07:14PM +0900, Takashi Sakamoto wrote: > > > > In a design of ALSA control core, each element can be pointed according > > to data of 'struct snd_ctl_elem_id'. There're two independent ways to > > indicate arbitrary element: > > 1. by 'numerical ID' (.numid) > > 2. by a combination of 'interface' (.iface), 'device' (.device), > > 'sub device' (.subdevice), 'name' (.name) and 'index' (.index). > > > > For our information, in ALSA control core, some elements with the same > > attributes are managed by data of 'struct snd_kcontrol'. I call it as > > 'element set'. The value of '.index' represents offset from the first > > element in the element set for a target element. > > > > I don't get your concern clearly. But it's my pleasure that the above > > information will help you if you missed the two ways. > > > > Right. Thanks. I understood all that... > > I've actually figured out a hack that will probably work fine to fix my > issue. Smatch provides a way to hand edit the cross function DB: > http://repo.or.cz/smatch.git/blob/HEAD:/smatch_data/db/fixup_kernel.sh > I can probably solve this by adding a few lines of code to that file. > I'm testing it now. > > What I was trying to say was even though we don't need to check .index > since we're not using it, it would simplify static analysis if we would > would set it to zero. It shouldn't hurt anything since we're not going > to use it. Actually the value index is copied from the kctl->id before calling the get and put callbacks. In snd_ctl_elem_read() and snd_ctl_elem_write(), both call snd_ctl_build_ioff() just before kctl->get() and kctl->put() calls. This overwrites both index and numid fields with the correction of the offset. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
