All of lore.kernel.org
 help / color / mirror / Atom feed
From: Takashi Iwai <tiwai@suse.de>
To: Vladimir Sadovnikov <sadko4u@gmail.com>
Cc: Daniel Sales <daniel.sales.z@gmail.com>,
	alsa-devel@alsa-project.org, "Geoffrey D. Bennett" <g@b4.vu>,
	Markus Schroetter <project.m.schroetter@gmail.com>,
	Alex Fellows <alex.fellows@gmail.com>
Subject: Re: [PATCH 0/2] ALSA: usb-audio: scarlett2: Read all configuration at init time
Date: Mon, 07 Jun 2021 17:12:38 +0200	[thread overview]
Message-ID: <s5hfsxtemjd.wl-tiwai@suse.de> (raw)
In-Reply-To: <3c7a458a-a5cd-08e4-a462-293c5bf633ec@gmail.com>

On Mon, 07 Jun 2021 17:00:10 +0200,
Vladimir Sadovnikov wrote:
> 
> Hello!
> 
> I would like to say some words from my side.
> 
> The Scarlett device (especially 18i20) is pretty complicated device
> and holds a lot of settings in it's internal
> configuration area (hardware and software).
> 
> So this is not the only patch which will configure the driver in proper way.
> Since the device stores it's internal state (and that's good for power
> safety and mobility), ideally, we should get
> the almost fully compatible mixer settings with the original Focusrite
> Control Software.
> 
> The huge amount of job I've already done i my fork of Geoffrey's driver:
> https://github.com/sadko4u/focusrite-scarlett-backports/blob/master/prod-drv/mixer_scarlett_gen2.c
> 
> So we're planning to work on integrating our changes into the common
> patch sets and will submit changes here.

Sure, I don't mean against the patches, this looks like an acceptable
approach.  So don't worry, I'd take the patches once when the fixed
version is submitted.

However, from the system design POV, all those configurations should
be a software issue, and ideally we shouldn't  rely on the hardware
preset state which has been done *somehow* -- it may allow malfunction
easily.  One thing I've learned over years is that you can never trust
hardware :)


Takashi

> 
> Best,
> Vladimir
> 
> 07.06.2021 10:23, Takashi Iwai пишет:
> > On Sun, 06 Jun 2021 16:16:44 +0200,
> > Geoffrey D. Bennett wrote:
> >> These two patches add support for reading the mixer volumes and mux
> >> configuration from the hardware when the driver is initialising.
> >>
> >> Previously the ALSA volume controls were initialised to zero and the
> >> mux configuration set to a fixed default instead of being initialised
> >> to match the hardware state.
> >>
> >> The ALSA controls for the Scarlett Gen 2 interfaces should now always
> >> be in sync with the hardware. Thanks to Vladimir Sadovnikov for
> >> figuring out how to do this.
> >>
> >> Takashi, if these pass your review, I believe that they are
> >> appropriate for:
> >> #Cc: stable@vger.kernel.org
> > Well, in general, having a proper fixed value for the initial mixer
> > value is the right thing, which is a part of the driver's role.
> > Though, in snd-usb-audio, we don't set up the initial values just
> > because of laziness; since the topology in USB audio is variable per
> > device and often hard to parse correctly, it's difficult to determine
> > the suitable initial values, hence we leave untouched.  So, in that
> > sense, setting the zero isn't wrong, rather safer, per se.
> >
> > However, Scarlett 2 seems to want to be different; it has already some
> > initialization code to read the existing configs.  So this change
> > sounds more or less acceptable.  But it's questionable whether it's
> > really for stable as a "fix".
> >
> > In anyway, please fix the bug ktest bot spotted, the missing endian
> > conversions and resubmit.
> >
> >
> > thanks,
> >
> > Takashi
> 
> 

  parent reply	other threads:[~2021-06-07 15:13 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-06 14:16 [PATCH 0/2] ALSA: usb-audio: scarlett2: Read all configuration at init time Geoffrey D. Bennett
2021-06-06 14:16 ` [PATCH 1/2] ALSA: usb-audio: scarlett2: Read mixer volumes " Geoffrey D. Bennett
2021-06-06 14:32   ` Markus
2021-06-07  5:23   ` kernel test robot
2021-06-07  5:23     ` kernel test robot
2021-06-06 14:17 ` [PATCH 2/2] ALSA: usb-audio: scarlett2: Read mux " Geoffrey D. Bennett
2021-06-06 14:33   ` Markus
2021-06-07  7:23 ` [PATCH 0/2] ALSA: usb-audio: scarlett2: Read all configuration " Takashi Iwai
     [not found]   ` <3c7a458a-a5cd-08e4-a462-293c5bf633ec@gmail.com>
2021-06-07 15:12     ` Takashi Iwai [this message]
2021-06-07 17:18       ` Markus Schroetter
2021-06-07 19:51   ` Geoffrey D. Bennett

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=s5hfsxtemjd.wl-tiwai@suse.de \
    --to=tiwai@suse.de \
    --cc=alex.fellows@gmail.com \
    --cc=alsa-devel@alsa-project.org \
    --cc=daniel.sales.z@gmail.com \
    --cc=g@b4.vu \
    --cc=project.m.schroetter@gmail.com \
    --cc=sadko4u@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.