From: Clemens Ladisch <clemens@ladisch.de>
To: Zhen Fu <fuzh@marvell.com>
Cc: alsa-devel@alsa-project.org
Subject: Re: how to update hw_ptr and appl_ptr
Date: Tue, 26 Jun 2012 14:27:04 +0200 [thread overview]
Message-ID: <4FE9AA98.7000307@ladisch.de> (raw)
In-Reply-To: <DBBC59900F0EF340B9938F193FB1A3453605DD79@SC-VEXCH4.marvell.com>
Zhen Fu wrote:
> when DMA handler called snd_pcm_period_elapsed, so I want to know how
> about update hw_ptr in ALSA.
snd_pcm_period_elapsed() calls snd_pcm_update_hw_ptr0(), which calls
your driver's .pointer callback. The value returned by that callback
essentially is the hw_ptr (although it doesn't wrap around at the end
of the buffer).
Why do you care about hw_ptr?
Regards,
Clemens
next prev parent reply other threads:[~2012-06-26 12:27 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-26 5:40 how to update hw_ptr and appl_ptr Zhen Fu
2012-06-26 9:34 ` Clemens Ladisch
2012-06-26 9:37 ` Zhen Fu
2012-06-26 9:43 ` Zhen Fu
2012-06-26 12:27 ` Clemens Ladisch [this message]
2012-06-27 3:13 ` Zhen Fu
2012-06-27 19:24 ` Clemens Ladisch
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