* HDA driver without interrupt @ 2012-05-02 12:54 liufc 2012-05-02 19:28 ` Pierre-Louis Bossart 2012-05-03 6:13 ` Clemens Ladisch 0 siblings, 2 replies; 4+ messages in thread From: liufc @ 2012-05-02 12:54 UTC (permalink / raw) To: alsa-devel Hi guys,I'm trying to implement an alsa driver based on the Intel HDA driver.However due to some hardware defects,I'm not able to use interrupt.So I wonder whether there is a way to do the job without the help of interrupt.Can anyone give me a suggestion? ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: HDA driver without interrupt 2012-05-02 12:54 HDA driver without interrupt liufc @ 2012-05-02 19:28 ` Pierre-Louis Bossart 2012-05-03 6:13 ` Clemens Ladisch 1 sibling, 0 replies; 4+ messages in thread From: Pierre-Louis Bossart @ 2012-05-02 19:28 UTC (permalink / raw) To: alsa-devel On 5/2/2012 7:54 AM, liufc wrote: > Hi guys,I'm trying to implement an alsa driver based on the Intel HDA > driver.However due to some hardware defects,I'm not able to use > interrupt.So I wonder whether there is a way to do the job without the > help of interrupt.Can anyone give me a suggestion? What interrupt are you talking about? ALSA has the ability to discard periodic interrupts but the user-space code needs to explicitly request this mode (eg PulseAudio/AudioHAL). Regular/legacy apps do need an interrupt coming from the hardware. -Pierre ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: HDA driver without interrupt 2012-05-02 12:54 HDA driver without interrupt liufc 2012-05-02 19:28 ` Pierre-Louis Bossart @ 2012-05-03 6:13 ` Clemens Ladisch [not found] ` <CAOAAS1z7iA2excEt9cE45CBmQs=XUkigW6+A94zyp2BuRLBBcA@mail.gmail.com> 1 sibling, 1 reply; 4+ messages in thread From: Clemens Ladisch @ 2012-05-03 6:13 UTC (permalink / raw) To: liufc; +Cc: alsa-devel liufc wrote: > Hi guys,I'm trying to implement an alsa driver based on the Intel HDA > driver.However due to some hardware defects,I'm not able to use > interrupt. How does your hardware work then? Regards, Clemens ^ permalink raw reply [flat|nested] 4+ messages in thread
[parent not found: <CAOAAS1z7iA2excEt9cE45CBmQs=XUkigW6+A94zyp2BuRLBBcA@mail.gmail.com>]
* Re: HDA driver without interrupt [not found] ` <CAOAAS1z7iA2excEt9cE45CBmQs=XUkigW6+A94zyp2BuRLBBcA@mail.gmail.com> @ 2012-05-03 8:37 ` Clemens Ladisch 0 siblings, 0 replies; 4+ messages in thread From: Clemens Ladisch @ 2012-05-03 8:37 UTC (permalink / raw) To: Fanchao Liu; +Cc: alsa-devel Fanchao Liu wrote: > It can transfer data via DMA,the problem is I don't know when to > update hw_ptr and other pointers without interrupt. Does the hardware have some other means to at least read the current position? > I set a timer and call snd_pcm_period_elapsed() every 50ms but get > underrun error. With a call to snd_pcm_period_elapsed(), the driver guarantees that the current position is at or after the next period boundary. Regards, Clemens ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-05-03 8:33 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-05-02 12:54 HDA driver without interrupt liufc
2012-05-02 19:28 ` Pierre-Louis Bossart
2012-05-03 6:13 ` Clemens Ladisch
[not found] ` <CAOAAS1z7iA2excEt9cE45CBmQs=XUkigW6+A94zyp2BuRLBBcA@mail.gmail.com>
2012-05-03 8:37 ` Clemens Ladisch
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).