Re: [alsa-devel] [PATCH 3/3] Add ALSA driver for Atmel AC97 controller

On Wed, 04 Feb 2009 13:09:37 +0100 Takashi Iwai tiwai@suse.de wrote:

At Wed, 4 Feb 2009 12:48:34 +0100, Hans-Christian Egtvedt wrote:

<snipp>

...

+static int atmel_ac97c_playback_hw_params(struct snd_pcm_substream *substream,

• struct snd_pcm_hw_params *hw_params)
  

+{

• struct atmel_ac97c *chip =

snd_pcm_substream_chip(substream);

• int retval;
• retval = snd_pcm_lib_malloc_pages(substream,

params_buffer_bytes(hw_params));

• if (retval)

• return retval;
  

Should be a negative-check.

For some reason if I only check for < 0, then the buffer is not configured properly. Seems like the preallocation goes wrong for some reason.

Any pointers to why?

I do snd_pcm_new(), then snd_pcm_set_ops(), then snd_pcm_lib_preallocate_pages_for_all().

<snipp>