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From: Alan Young <Alan.Young@IEE.org>
To: alsa-devel@alsa-project.org
Subject: Difference between boundary and buffer_size
Date: Thu, 3 Nov 2016 09:11:04 +0000	[thread overview]
Message-ID: <581AFF28.5060500@IEE.org> (raw)

The code in the kernel, in /pcm_lib.c/ and /pcm_native.c/, uses fields 
buffer_size and boundary in struct snd_pcm_runtime. As far as I can see, 
there are always initialized to the same value. In what circumstance 
might they be different? There is clearly some relationship to 
hw_ptr_base, as illustrated by this repeated snipped from 
snd_pcm_update_hw_ptr0()

		hw_base += runtime->buffer_size;
		if (hw_base >= runtime->boundary) {
			hw_base = 0;
			crossed_boundary++;
		}
		new_hw_ptr = hw_base + pos;

Alan.

             reply	other threads:[~2016-11-03  9:11 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-03  9:11 Alan Young [this message]
2016-11-03 16:45 ` Difference between boundary and buffer_size Lars-Peter Clausen
2016-11-03 22:56   ` Lars-Peter Clausen
2016-11-03 20:01 ` Clemens Ladisch

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