From: Pavel Hofman <pavel.hofman@ivitera.com>
To: Jaroslav Kysela <perex@perex.cz>
Cc: alsa-devel <alsa-devel@alsa-project.org>
Subject: Re: Direct use of the DMA buffer?
Date: Mon, 20 Feb 2012 10:25:57 +0100 [thread overview]
Message-ID: <4F4211A5.7050104@ivitera.com> (raw)
In-Reply-To: <4F4210A6.8010902@perex.cz>
Dne 20.2.2012 10:21, Jaroslav Kysela napsal(a):
>>
>> Clemens, thanks a lot for the information. How does it work when the
>> alsa-lib chain contains plugins, such as plug, rate, etc.? I would
>> assume the application circumvents these.
>
> Nope. The mmap commit mechanism was introduced to keep the plugin
> interface functional. The direct mmap access to the DMA buffer is only
> applied for the direct hw: devices. If a plugin is used inside alsa-lib,
> the application talks to the plugin chain (it means that an intermediate
> buffer for samples can be allocated to let things working).
>
Jaroslav, thanks a lot for the clarification.
Pavel.
prev parent reply other threads:[~2012-02-20 9:25 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-19 23:11 Direct use of the DMA buffer? Pavel Hofman
2012-02-20 8:11 ` Clemens Ladisch
2012-02-20 8:38 ` Pavel Hofman
[not found] ` <4F4210A6.8010902@perex.cz>
2012-02-20 9:22 ` Jaroslav Kysela
2012-02-20 9:25 ` Pavel Hofman [this message]
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