Re: [RFC] [ALSA][CONTROL] Added 2 ioctls for reading/writing values of multiple controls in one go (at once)

[Takashi Iwai <tiwai@suse.de>]

On Thu, 02 Feb 2017 04:45:48 +0100,
Takashi Sakamoto wrote:
> 
> Hi,
> 
> On Feb 2 2017 12:14, Satendra Singh Thakur wrote:
> > From: satendra singh thakur <satendra.t@samsung.com>
> >
> > -Added 2 ioctls in alsa driver's control interface
> > -Added an ioctl to read values of multiple elements at once
> > -Added an ioctl to write values of multiple elements at once
> > -In the absence of above ioctls user needs to call N ioctls to
> >  read/write value of N elements which requires N context switches
> > -Proposed ioctls will allow accessing N elements' values in a single
> >  context switch
> > -Above mentioned ioctl will be useful for alsa utils such as amixer
> >  which reads all controls of given sound card
> >
> > Signed-off-by: Satendra Singh Thakur <satendra.t@samsung.com>
> > ---
> >  include/uapi/sound/asound.h |    8 +++++
> >  sound/core/control.c        |   69 +++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 77 insertions(+)
> 
> I'm _strongly_ interested in your two patches, because it has a
> potentiality to purge ASoC abuse of TLV feature, which was introduced
> in  2014 with a bad reviewing process.

I don't think it can be a replacement for the extended TLV usages.
The proposed API is nothing but a loop of ctl elem read/write, and I'm
not sure whether it worth to introduce the new ioctls just for that.


Takashi