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From: Lee Revell <rlrevell@joe-job.com>
To: Carlos Munoz <carlos@kenati.com>
Cc: Valdis.Kletnieks@vt.edu, linux-kernel@vger.kernel.org,
	alsa-devel <alsa-devel@lists.sourceforge.net>
Subject: Re: How can I link the kernel with libgcc ?
Date: Thu, 09 Mar 2006 22:22:41 -0500	[thread overview]
Message-ID: <1141960963.13319.116.camel@mindpipe> (raw)
In-Reply-To: <4410EC0D.3090303@kenati.com>

(added alsa-devel to cc:)

On Thu, 2006-03-09 at 19:01 -0800, Carlos Munoz wrote:
> >Audio drivers should never have to directly manipulate the samples -
> >they just manage the DMA buffers and interrupts and wake up the process
> >at the right time.  Mixing, routing, volume control, DSP go in
> >userspace.
>
> Unfortunately, the driver needs to populate several coefficient tables 
> for the hardware to perform silence suppression and other advance 
> features. The values for these tables are calculated using log10 
> operations. I don't  see a clean way to push these operations to user 
> space without the need for custom applications that build the tables and 
> pass them to the driver.

Unless you can do it with fixed point math, or use a static table, you
might have to do just that, with a sysfs interface.  For example the
emu10k1 driver uses an ioctl interface to upload code to the built in
(floating point) DSP.  But new ioctls are frowned upon...

Lee



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       reply	other threads:[~2006-03-10  3:22 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <4410D9F0.6010707@kenati.com>
     [not found] ` <200603100145.k2A1jMem005323@turing-police.cc.vt.edu>
     [not found]   ` <1141956362.13319.105.camel@mindpipe>
     [not found]     ` <4410EC0D.3090303@kenati.com>
2006-03-10  3:22       ` Lee Revell [this message]
     [not found]       ` <4410F1BE.7000904@kenati.com>
2006-03-10  3:25         ` How can I link the kernel with libgcc ? Lee Revell
2006-03-10  3:47           ` Carlos Munoz
2006-03-10 10:37             ` Denis Vlasenko
2006-03-10 11:05               ` Bart Hartgers
2006-03-10 18:03               ` Carlos Munoz
2006-03-10 18:33                 ` linux-os (Dick Johnson)
2006-03-10 18:41                   ` Ben Slusky
2006-03-10 19:18                 ` Al Viro
2006-03-10 20:04                   ` Carlos Munoz
2006-03-10 11:55             ` James Courtier-Dutton

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