* About ALSA dummy module: support customized mixer volume leveling
@ 2022-09-08 5:26 YJ Lee
2022-09-08 8:16 ` Takashi Iwai
0 siblings, 1 reply; 5+ messages in thread
From: YJ Lee @ 2022-09-08 5:26 UTC (permalink / raw
To: tiwai; +Cc: alsa-devel, Ching Yun Chang, Yu-Hsuan Hsu
Hello Takashi (and the alsa community),
This is YJ Lee from chromium.org.
I'm thinking about extending the ALSA dummy module to support
customized volume leveling. It will be very useful to test devices
with different volume granularity. Currently this module is using
hard-coded mixer volume leveling, from min=-50 to max=100.
See L716: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/tree/sound/drivers/dummy.c?h=queue/5.19#n716
My plan (A) is to expose 2 more additional module parameters and
replace a few occurrences, from L742-750.
Another plan (B) is to leverage the current existing module
parameter:model, and make the dummy-module to be able to accept models
with customized volume leveling. New dummy models can be provided as
configuration files, and be used in the same way as how currently
existing dummy models (L146-213) are used. However, it's a bit
over-engineering from the original purpose.
What do you think about these plans? Any insight you (and the alsa
community) can provide will be greatly appreciated.
Best,
YJ
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: About ALSA dummy module: support customized mixer volume leveling
2022-09-08 5:26 About ALSA dummy module: support customized mixer volume leveling YJ Lee
@ 2022-09-08 8:16 ` Takashi Iwai
2022-09-08 10:32 ` YJ Lee
0 siblings, 1 reply; 5+ messages in thread
From: Takashi Iwai @ 2022-09-08 8:16 UTC (permalink / raw
To: YJ Lee; +Cc: alsa-devel, Ching Yun Chang, tiwai, Yu-Hsuan Hsu
On Thu, 08 Sep 2022 07:26:02 +0200,
YJ Lee wrote:
>
> Hello Takashi (and the alsa community),
>
> This is YJ Lee from chromium.org.
>
> I'm thinking about extending the ALSA dummy module to support
> customized volume leveling. It will be very useful to test devices
> with different volume granularity. Currently this module is using
> hard-coded mixer volume leveling, from min=-50 to max=100.
>
> See L716: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/tree/sound/drivers/dummy.c?h=queue/5.19#n716
>
> My plan (A) is to expose 2 more additional module parameters and
> replace a few occurrences, from L742-750.
>
> Another plan (B) is to leverage the current existing module
> parameter:model, and make the dummy-module to be able to accept models
> with customized volume leveling. New dummy models can be provided as
> configuration files, and be used in the same way as how currently
> existing dummy models (L146-213) are used. However, it's a bit
> over-engineering from the original purpose.
>
> What do you think about these plans? Any insight you (and the alsa
> community) can provide will be greatly appreciated.
Only for volume min/max, module options may be an easier way, IMO.
OTOH, if we want to adjust more stuff, another possibility is to
extend the proc file. It currently supports the dynamic changes of
PCM parameters, but we can extend it or add a new proc file for
adjusting other stuff, too. So the question is what else we want to
allow changing.
thanks,
Takashi
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: About ALSA dummy module: support customized mixer volume leveling
2022-09-08 8:16 ` Takashi Iwai
@ 2022-09-08 10:32 ` YJ Lee
2022-09-08 12:38 ` Takashi Iwai
0 siblings, 1 reply; 5+ messages in thread
From: YJ Lee @ 2022-09-08 10:32 UTC (permalink / raw
To: Takashi Iwai; +Cc: alsa-devel, Ching Yun Chang, tiwai, Yu-Hsuan Hsu
On Thu, Sep 8, 2022 at 4:16 PM Takashi Iwai <tiwai@suse.de> wrote:
>
> On Thu, 08 Sep 2022 07:26:02 +0200,
> YJ Lee wrote:
> >
> > Hello Takashi (and the alsa community),
> >
> > This is YJ Lee from chromium.org.
> >
> > I'm thinking about extending the ALSA dummy module to support
> > customized volume leveling. It will be very useful to test devices
> > with different volume granularity. Currently this module is using
> > hard-coded mixer volume leveling, from min=-50 to max=100.
> >
> > See L716: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/tree/sound/drivers/dummy.c?h=queue/5.19#n716
> >
> > My plan (A) is to expose 2 more additional module parameters and
> > replace a few occurrences, from L742-750.
> >
> > Another plan (B) is to leverage the current existing module
> > parameter:model, and make the dummy-module to be able to accept models
> > with customized volume leveling. New dummy models can be provided as
> > configuration files, and be used in the same way as how currently
> > existing dummy models (L146-213) are used. However, it's a bit
> > over-engineering from the original purpose.
> >
> > What do you think about these plans? Any insight you (and the alsa
> > community) can provide will be greatly appreciated.
>
> Only for volume min/max, module options may be an easier way, IMO.
>
> OTOH, if we want to adjust more stuff, another possibility is to
> extend the proc file. It currently supports the dynamic changes of
> PCM parameters, but we can extend it or add a new proc file for
> adjusting other stuff, too. So the question is what else we want to
> allow changing.
>
>
> thanks,
>
> Takashi
Hi Takashi,
Thanks for your quick reply! I can't express my gratitude enough. Will
stick with plan (A).
Additionally, I'll take some time to read it and learn how to use the
proc file. Compared with snd-dummy, I've plugged in a physical USB
headset and saw some read-only files (usb*) under /proc/asound/cardX.
By extending the proc file, are you suggesting we can change those
into writable so ALSA will understand and make corresponding changes,
(e.g. 'change' the dummy card into a USB sound card)? Can you tell me
more about how to extend or add a new proc file (as a separate topic)?
Again, greatly appreciated.
Best,
YJ
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: About ALSA dummy module: support customized mixer volume leveling
2022-09-08 10:32 ` YJ Lee
@ 2022-09-08 12:38 ` Takashi Iwai
2022-09-08 12:53 ` YJ Lee
0 siblings, 1 reply; 5+ messages in thread
From: Takashi Iwai @ 2022-09-08 12:38 UTC (permalink / raw
To: YJ Lee; +Cc: alsa-devel, Ching Yun Chang, tiwai, Yu-Hsuan Hsu
On Thu, 08 Sep 2022 12:32:14 +0200,
YJ Lee wrote:
>
> On Thu, Sep 8, 2022 at 4:16 PM Takashi Iwai <tiwai@suse.de> wrote:
> >
> > On Thu, 08 Sep 2022 07:26:02 +0200,
> > YJ Lee wrote:
> > >
> > > Hello Takashi (and the alsa community),
> > >
> > > This is YJ Lee from chromium.org.
> > >
> > > I'm thinking about extending the ALSA dummy module to support
> > > customized volume leveling. It will be very useful to test devices
> > > with different volume granularity. Currently this module is using
> > > hard-coded mixer volume leveling, from min=-50 to max=100.
> > >
> > > See L716: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/tree/sound/drivers/dummy.c?h=queue/5.19#n716
> > >
> > > My plan (A) is to expose 2 more additional module parameters and
> > > replace a few occurrences, from L742-750.
> > >
> > > Another plan (B) is to leverage the current existing module
> > > parameter:model, and make the dummy-module to be able to accept models
> > > with customized volume leveling. New dummy models can be provided as
> > > configuration files, and be used in the same way as how currently
> > > existing dummy models (L146-213) are used. However, it's a bit
> > > over-engineering from the original purpose.
> > >
> > > What do you think about these plans? Any insight you (and the alsa
> > > community) can provide will be greatly appreciated.
> >
> > Only for volume min/max, module options may be an easier way, IMO.
> >
> > OTOH, if we want to adjust more stuff, another possibility is to
> > extend the proc file. It currently supports the dynamic changes of
> > PCM parameters, but we can extend it or add a new proc file for
> > adjusting other stuff, too. So the question is what else we want to
> > allow changing.
> >
> >
> > thanks,
> >
> > Takashi
>
> Hi Takashi,
>
> Thanks for your quick reply! I can't express my gratitude enough. Will
> stick with plan (A).
>
> Additionally, I'll take some time to read it and learn how to use the
> proc file. Compared with snd-dummy, I've plugged in a physical USB
> headset and saw some read-only files (usb*) under /proc/asound/cardX.
> By extending the proc file, are you suggesting we can change those
> into writable so ALSA will understand and make corresponding changes,
> (e.g. 'change' the dummy card into a USB sound card)? Can you tell me
> more about how to extend or add a new proc file (as a separate topic)?
Some proc files allow writing, and the dummy driver's own proc file is
such one (enabled only when CONFIG_SND_DEBUG=y, though). The proc
file is created with snd_card_rw_proc_new() and the passed write
callback is dummy_proc_write() in this case. It parses each text line
and overrides the existing struct field accordingly.
HTH,
Takashi
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: About ALSA dummy module: support customized mixer volume leveling
2022-09-08 12:38 ` Takashi Iwai
@ 2022-09-08 12:53 ` YJ Lee
0 siblings, 0 replies; 5+ messages in thread
From: YJ Lee @ 2022-09-08 12:53 UTC (permalink / raw
To: Takashi Iwai; +Cc: alsa-devel, Ching Yun Chang, tiwai, Yu-Hsuan Hsu
On Thu, Sep 8, 2022 at 8:38 PM Takashi Iwai <tiwai@suse.de> wrote:
>
> On Thu, 08 Sep 2022 12:32:14 +0200,
> YJ Lee wrote:
> >
> > On Thu, Sep 8, 2022 at 4:16 PM Takashi Iwai <tiwai@suse.de> wrote:
> > >
> > > On Thu, 08 Sep 2022 07:26:02 +0200,
> > > YJ Lee wrote:
> > > >
> > > > Hello Takashi (and the alsa community),
> > > >
> > > > This is YJ Lee from chromium.org.
> > > >
> > > > I'm thinking about extending the ALSA dummy module to support
> > > > customized volume leveling. It will be very useful to test devices
> > > > with different volume granularity. Currently this module is using
> > > > hard-coded mixer volume leveling, from min=-50 to max=100.
> > > >
> > > > See L716: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/tree/sound/drivers/dummy.c?h=queue/5.19#n716
> > > >
> > > > My plan (A) is to expose 2 more additional module parameters and
> > > > replace a few occurrences, from L742-750.
> > > >
> > > > Another plan (B) is to leverage the current existing module
> > > > parameter:model, and make the dummy-module to be able to accept models
> > > > with customized volume leveling. New dummy models can be provided as
> > > > configuration files, and be used in the same way as how currently
> > > > existing dummy models (L146-213) are used. However, it's a bit
> > > > over-engineering from the original purpose.
> > > >
> > > > What do you think about these plans? Any insight you (and the alsa
> > > > community) can provide will be greatly appreciated.
> > >
> > > Only for volume min/max, module options may be an easier way, IMO.
> > >
> > > OTOH, if we want to adjust more stuff, another possibility is to
> > > extend the proc file. It currently supports the dynamic changes of
> > > PCM parameters, but we can extend it or add a new proc file for
> > > adjusting other stuff, too. So the question is what else we want to
> > > allow changing.
> > >
> > >
> > > thanks,
> > >
> > > Takashi
> >
> > Hi Takashi,
> >
> > Thanks for your quick reply! I can't express my gratitude enough. Will
> > stick with plan (A).
> >
> > Additionally, I'll take some time to read it and learn how to use the
> > proc file. Compared with snd-dummy, I've plugged in a physical USB
> > headset and saw some read-only files (usb*) under /proc/asound/cardX.
> > By extending the proc file, are you suggesting we can change those
> > into writable so ALSA will understand and make corresponding changes,
> > (e.g. 'change' the dummy card into a USB sound card)? Can you tell me
> > more about how to extend or add a new proc file (as a separate topic)?
>
> Some proc files allow writing, and the dummy driver's own proc file is
> such one (enabled only when CONFIG_SND_DEBUG=y, though). The proc
> file is created with snd_card_rw_proc_new() and the passed write
> callback is dummy_proc_write() in this case. It parses each text line
> and overrides the existing struct field accordingly.
>
>
> HTH,
>
> Takashi
Hi Takashi,
This greatly helps! Thanks so much for your kind explanation : )
Best,
YJ
^ permalink raw reply [flat|nested] 5+ messages in thread
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2022-09-08 5:26 About ALSA dummy module: support customized mixer volume leveling YJ Lee
2022-09-08 8:16 ` Takashi Iwai
2022-09-08 10:32 ` YJ Lee
2022-09-08 12:38 ` Takashi Iwai
2022-09-08 12:53 ` YJ Lee
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