From: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
To: alsa-devel@alsa-project.org
Subject: Can DMA address, periods, buffer size, etc change after hw_params is called?
Date: Thu, 29 Jan 2009 08:18:25 +0100 [thread overview]
Message-ID: <20090129081825.241be9e4@hcegtvedt> (raw)
Hi,
I wonder if I must take care handling changes in DMA address, number of
periods and period size in the prepare callback?
Or are these locked after the first time prepare is called?
The reason I ask is because I'm developing a new ALSA driver and I
prepare a cyclic DMA transfer in the first prepare callback. Additional
calls to prepare will not do anything DMA stuff.
The cyclic DMA transfer is then released in the close callback.
Should I after the open and hw_params calls be ready to handle any
change at all regarding DMA buffer address, periods and/or number of
periods?
I hope I made sense in this email (-:
--
Best regards,
Hans-Christian Egtvedt
next reply other threads:[~2009-01-29 7:18 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-29 7:18 Hans-Christian Egtvedt [this message]
2009-01-29 8:11 ` Can DMA address, periods, buffer size, etc change after hw_params is called? Clemens Ladisch
2009-01-29 8:43 ` Hans-Christian Egtvedt
2009-01-29 8:58 ` Clemens Ladisch
2009-01-29 9:35 ` Hans-Christian Egtvedt
2009-01-29 9:59 ` Clemens Ladisch
2009-01-29 10:10 ` Hans-Christian Egtvedt
2009-01-29 22:30 ` Timur Tabi
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