On Wed, Sep 30, 2020 at 11:46:16AM +0200, Pali Rohár wrote:
> On Wednesday 30 September 2020 11:20:43 Greg Kroah-Hartman wrote:
> > On Wed, Sep 30, 2020 at 10:25:34AM +0200, Pali Rohár wrote:
> > > On Wednesday 30 September 2020 10:02:05 Greg Kroah-Hartman wrote:
> > > > On Tue, Sep 29, 2020 at 11:32:54PM +0200, Pali Rohár wrote:
> > > > > CCing other lists and maintainers, hopefully, somebody would have a 
> > > > > time to look at it...
> > > > > 
> > > > > On Saturday 08 August 2020 15:27:47 Pali Rohár wrote:
> > > > > > On Wednesday 15 April 2020 00:56:18 Pali Rohár wrote:
> > > > > > > On Sunday 09 February 2020 14:21:37 Pali Rohár wrote:
> > > > > > > > On Saturday 04 January 2020 11:24:36 Pali Rohár wrote:
> > > > > > > > > On Saturday 04 January 2020 10:44:52 Marcel Holtmann wrote:
> > > > > > > > > > Hi Pali,
> > > > > > > > > > 
> > > > > > > > > > > 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?
> > > 
> > > Hello! Marcel in January wrote that access for HCI commands is being
> > > removed from kernel. I do not know if he managed to do it in since
> > > January, but I'm going to check it...
> > 
> > So you don't see a regression/problem, but are saying there is one?
> 
> Hello!
> 
> Planed removal of used API would be a regression. Marcel wrote that it
> is "being removed". Nobody reacted to that fact for 10 months so I did
> not know if this comment was lost and removal is already in progress.
> Or if something was changed and removal is not planned anymore.
> 
> So are you aware that it will break applications?

Does it?

> > odd...
> 
> I think it is not a good idea to do something and then check what happen
> if there are people who know that such thing is in use and for sure it
> will break something.
> 
> And also I still did not get any response what is the replacement of
> that API.

It sounds like only new commands are restricted, so how is that a
regression?

thanks,

greg k-h

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