RE: [PATCH v10 10/10] Bluetooth: Add offload feature under experimental flag

["K, Kiran" <kiran.k@intel.com>]

Hi Luiz, Marcel,

> -----Original Message-----
> From: Marcel Holtmann <marcel@holtmann.org>
> Sent: Friday, July 23, 2021 12:21 AM
> To: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
> Cc: K, Kiran <kiran.k@intel.com>; linux-bluetooth@vger.kernel.org
> Subject: Re: [PATCH v10 10/10] Bluetooth: Add offload feature under
> experimental flag
> 
> Hi Luiz,
> 
> >>>>>> Allow user level process to enable / disable codec offload
> >>>>>> feature through mgmt interface. By default offload codec feature
> >>>>>> is disabled.
> >>>>>>
> >>>>>> Signed-off-by: Kiran K <kiran.k@intel.com>
> >>>>>> Reviewed-by: Chethan T N <chethan.tumkur.narayan@intel.com>
> >>>>>> Reviewed-by: Srivatsa Ravishankar
> >>>>>> <ravishankar.srivatsa@intel.com>
> >>>>>> ---
> >>>>>> * changes in v10:
> >>>>>> - new patch added to place offload codec feature under
> >>>>>> experimental flag
> >>>>>>
> >>>>>> include/net/bluetooth/hci.h |   4 ++
> >>>>>> net/bluetooth/mgmt.c        | 106
> +++++++++++++++++++++++++++++++++++-
> >>>>>> net/bluetooth/sco.c         |  10 ++++
> >>>>>> 3 files changed, 119 insertions(+), 1 deletion(-)
> >>>>>>
> >>>>>> diff --git a/include/net/bluetooth/hci.h
> >>>>>> b/include/net/bluetooth/hci.h index e20318854900..5ca98d9f64dd
> >>>>>> 100644
> >>>>>> --- a/include/net/bluetooth/hci.h
> >>>>>> +++ b/include/net/bluetooth/hci.h
> >>>>>> @@ -331,6 +331,10 @@ enum {
> >>>>>>      HCI_CMD_PENDING,
> >>>>>>      HCI_FORCE_NO_MITM,
> >>>>>>
> >>>>>> +#if IS_ENABLED(CONFIG_BT_OFFLOAD_CODECS)
> >>>>>> +       HCI_OFFLOAD_CODECS_ENABLED, #endif
> >>>>>
> >>>>> That is probably a bad idea as it could lead the enum to assume
> >>>>> different values based on what is enabled, besides we don't gain
> >>>>> anything by not having the symbol defined all the time.
> >>>>
> >>>> While this would work with dev_flags which are internal and not API, I
> still don’t like it.
> >>>>
> >>>> There is really no benefit to make this a compile time option. And as far
> as I remember I never said this needs to be compile time. Actually I rather
> have this as an experimental setting so that it can be switched on at runtime.
> Nobody is going to recompile their kernels to test codec offload.
> >>>
> >>> Initially I was with the same opinion, but the problem is the codecs
> >>> are read at init sequence and the experimental flags are set at a
> >>> later stage thus why I suggested a KConfig option until the feature
> >>> is more mature and we can remove the option altogether.
> >>
> >> I am fine with the codec options being read all the time. I mean having an
> experimental option to control the use of offload.
> >
> > Alright, then we don't need the Kconfig after all, the experimental
> > flag will only control the use of the codecs e.g. socketopts would not
> > work if the flag is not enabled I assume?
> 
> exactly. It would then return EOPNOTSUPP error. It would be similar to an old
> kernel where this socket option is not available either.

Ack. I will send the changes in the next patchset.

> 
> Regards
> 
> Marcel

Regards,
Kiran