On Tue, 22 Aug 2017 01:42:19 +0200, Takashi Sakamoto wrote: > > Hi, > > This patchset is to avoid a trouble on ALSA control core, kernel API of > ALSA control component and ALSA control interface/protocol to handle TLV > operations from user space. > > In a design of ALSA control core, a set of elements is represented by > 'struct snd_kcontrol' to share common attributes. The set of elements > shares TLV (Type-Length-Value) data, too. > > On the other hand, in ALSA control interface/protocol for applications, > a TLV operation is committed to an element. Totally, the operation can > have sub-effect to the other elements in the set. For example, TLV_WRITE > operation is expected to change TLV data, which returns to applications. > Applications attempt to change the TLV data per element, but in the above > design, they can effect to elements in the same set. > > As a default, ALSA control core has no implementation except for TLV_READ > operation. Thus, the above design looks to have no issue. However, in > kernel APIs of ALSA control component, developers can program a handler > for any request of the TLV operation. Therefore, for elements in a set > which has the handler, applications can commit TLV_WRITE and TLV_COMMAND > requests. > > For the above scenario, ALSA control core assist notification. When the > handler returns positive value, the core queueing an event for a requested > element. However, this includes design defects that the event is not > queued for the other element in a set. Actually, developers can program > the handlers to keep per-element TLV data, but it depends on each driver. > > In this patchset, I attempts to solve the above issue, by delegating the > event notification to each driver of ALSA control component. > > Additionally, this patchset includes a solution against an issue in below > message thread: > > snd_ctl_add_enumerated_elem_set and TLV > http://mailman.alsa-project.org/pipermail/alsa-devel/2017-July/123364.html > > > Takashi Sakamoto (3): > ALSA: control: delegate TLV eventing to each driver > ALSA: control: queue TLV event for all of elements in an user-defined > set > ALSA: control: disable TLV data at initial state of user-defined > element set The patch set looks OK to me through a quick glance. If it's confirmed to work with your tests, feel free to resubmit as the patches for merge. thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
