At Wed, 28 Jun 2006 14:40:42 +0200 (CEST), Jaroslav Kysela wrote: > > On Wed, 28 Jun 2006, Takashi Iwai wrote: > > > At Wed, 28 Jun 2006 13:57:50 +0200 (CEST), > > Jaroslav Kysela wrote: > > > > > > Hi, > > > > > > here is the final TLV update. The patch bellow will add: > > > > > > - TLV write support > > > - TLV callback mechanism for lowlevel drivers > > > - TLV change notification > > > - TLV ioctl support for user space control elements > > > > This implementation seems inconsistent. > > > > Suppose you inquire an attribute via TLV_WRITE. From the apps POV, it > > doesn't matter whether the mixer element is user-defined or not. When > > alsa-lib issues ioctl(TLV_WRITE) to a user-defined element, it > > replaces the TLV list with the inquiry TLV but cannot return any > > useful value. > > Yes, but that's the way how user control elements works. No, the question is how to pass the TLV list. Using the same ioctl for completely different purposes is confusing. > The similar > situation is for the element value where no "back to user space callback" > exists so the written values cannot be verified. Sorry what do you mean? The elements without tlv write support? In that case, you can know the TLV-WRITE ioctl is invalid for that element beforehand. > If you want the "correct" > behaviour, an another layer must be designed and we may call these > elements as user-defined version 2. Urgh, it's a bad strategy to assume the next version before implementing the first version. > Also, an app which manages the user > TLV value can mark the access only for read (although writting will be > also possible). This sounds like a good workaround although still inconsistency remains (the access is allowed even though the flag bits not set). Also, if we do in this way, it should be a job of alsa-lib rather than apps. But honestly, I'm not for committing the kernel-code changes to the mainstream before actually testing -- especially if it's involved with the API definition. Takashi Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-devel
