On Wed, Sep 30, 2020 at 10:16:40AM +0200, Marcel Holtmann wrote: > Hi Greg, > > >>>>>>>> I wrote a simple script "sco_features.pl" which show all supported > >>>>>>>> codecs by local HCI bluetooth adapter. Script is available at: > >>>>>>>> > >>>>>>>> https://github.com/pali/hsphfpd-prototype/blob/prototype/sco_features.pl > >>>>>>>> > >>>>>>>> And I found out that OCF_READ_LOCAL_CODECS HCI command cannot be > >>>>>>>> send by > >>>>>>>> non-root user. Kernel returns "Operation not permitted" error. > >>>>>>>> > >>>>>>>> What is reason that kernel blocks OCF_READ_LOCAL_CODECS command for > >>>>>>>> non-root users? Without it (audio) application does not know which > >>>>>>>> codecs local bluetooth adapter supports. > >>>>>>>> > >>>>>>>> E.g. OCF_READ_LOCAL_EXT_FEATURES or OCF_READ_VOICE_SETTING commands > >>>>>>>> can > >>>>>>>> be send also by non-root user and kernel does not block them. > >>>>>>> > >>>>>>> actually the direct access to HCI commands is being removed. So we > >>>>>>> have no plans to add new commands into the list since that it what > >>>>>>> the kernel is suppose to handle. If we wanted to expose this, then it > >>>>>>> has to be via mgmt. > >>>>>> > >>>>>> Hi Marcel! Thank you for information. I have not know that this API is > >>>>>> "deprecated" and is going to be removed. But userspace audio > >>>>>> applications need to know what bluetooth adapter supports, so can you > >>>>>> export result of these commands to userspace? My script linked above > >>>>>> calls: OCF_READ_VOICE_SETTING, OCF_READ_LOCAL_COMMANDS, > >>>>>> OCF_READ_LOCAL_EXT_FEATURES, OCF_READ_LOCAL_CODECS > >>>>> > >>>>> Hello! Just a gently reminder for this question. How to retrieve > >>>>> information about supported codecs from userspace by non-root user? > >>>>> Because running all bluetooth audio applications by root is not really a > >>>>> solution. Plus if above API for root user is going to be removed, what > >>>>> is a replacement? > >>>> > >>>> Hello! > >>>> > >>>> I have not got any answer to my email from Marcel for months, so I'm > >>>> adding other developers to loop. Could somebody tell me that is the > >>>> replacement API if above one is going to be removed? > >>>> > >>>> I was not able to find any documentation where could be described this > >>>> API nor information about deprecation / removal. > >>>> > >>>> And are you aware of the fact that removing of API could potentially > >>>> break existing applications? > >>>> > >>>> I really need to know which API should I use, because when I use API > >>>> which is going to be removed, then my application stops working. And I > >>>> really want to avoid it. > >>>> > >>>> Also I have not got any response yet, how can I read list of supported > >>>> codecs by bluetooth adapter by ordinary non-root user? Audio application > >>>> needs to know list of supported codecs and it is really insane to run it > >>>> as root. > >>> > >>> Hello! This is just another reminder that I have not got any reply to > >>> this email. > >>> > >>> Does silence mean that audio applications are expected to work only > >>> under root account and ordinary users are not able to use audio and list > >>> supported codecs? > >> > >> Hello! I have not got any reply for this issue for 10 months and if you > >> are going to remove (or after these 10 months you already did it?) > >> existing HCI API from kernel it would break existing and working > >> userspace application. How do you want to handle such regressions? > > > > What git commit caused this regression? > > there is no regression! > > New Bluetooth standards added new HCI commands that are just not > exposed to unprivileged users.
Ok, that makes sense. What tool takes advantage of these new HCI commands? thanks, greg k-h
