[alsa-devel] snd_pcm_ops - .copy
Harsha priya gupta
harshapriya at gmail.com
Tue Apr 22 04:38:06 CEST 2008
On Tue, Apr 22, 2008 at 8:07 AM, Harsha priya gupta <harshapriya at gmail.com>
> I am not using the mmap method. How can i make sure that everytime a user
> buffer is passed to driver, my copy function would be called?
> On Mon, Apr 21, 2008 at 9:30 PM, Takashi Iwai <tiwai at suse.de> wrote:
> > At Mon, 21 Apr 2008 19:27:45 +0530,
> > Harsha priya gupta wrote:
> > >
> > > Hi,
> > > I am trying to implement the .copy function of playack_ops in my
> > driver. But
> > > when I try playing an mp3 file, my .copy's function code path was
> > executing.
> > > Suddenly I do not see that function being called. Can anyone help me
> > > understand when the following code path will be executed
> > >
> > > snd_pcm_lib_write_transfer
> > > substream->ops->copy
> > Do you use a mmap method? If so, the copy callback won't be called.
> > The copy callback is only for copying the data from the user-space
> > buffer to the driver buffer, which is skipped via mmap.
> > Takashi
More information about the Alsa-devel