[alsa-devel] Input/output error while playing a file using aplay

[Pharaoh .]

static snd_pcm_uframes_t audio_get_dma_pos(struct audio_stream *s)
{
        snd_pcm_substream_t *substream = s->stream;
        snd_pcm_runtime_t *runtime = substream->runtime;
        unsigned long flags;
        dma_addr_t count;
        unsigned long offset;
        dma_addr_t src,dest;

         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
                spin_lock_irqsave(&s->dma_lock, flags);
                dest = omap_get_dma_dst_pos(s->lch[s->dma_q_head]);
                offset = dest - runtime->dma_addr;
                spin_unlock_irqrestore(&s->dma_lock, flags);
                printk("dest is %u and offset is %u\n",dest,offset);
         } else {
                spin_lock_irqsave(&s->dma_lock, flags);
                src = omap_get_dma_src_pos(s->lch[s->dma_q_head]);
                offset = src - runtime->dma_addr;
                spin_unlock_irqrestore(&s->dma_lock, flags);
                printk("src is %u and offset is %u\n",dest,offset);
         }

        return bytes_to_frames(substream->runtime, offset);
}

and the log is as same....still no joy..

First time

snd_omap_alsa_pointer start
src is 3246792928 and offset is 3296722944
Returning pos = 18874368
Inside snd_pcm_update_hw_ptr_pos, pos is 18874368
ALSA sound/core/pcm_lib.c:167: BUG: stream = 0, pos = 0x1200000,
buffer size = 0x4000, period size = 0x800
returning pos 18874368

.......
.......
Second time

snd_omap_alsa_pointer start
src is 3246792928 and offset is 3296722944
Returning pos = 18874368
Inside snd_pcm_update_hw_ptr_pos, pos is 18874368
ALSA sound/core/pcm_lib.c:167: BUG: stream = 0, pos = 0x1200000,
buffer size = 0x4000, period size = 0x800
returning pos 18874368

......

then it hangs in the omap_request_dma function.

On 6/26/07, Pharaoh . <pharaoh137 at gmail.com> wrote:
> wait..wait.....I need to use locking here...let me send you log after
> doing locking appropriately .....
>
> On 6/26/07, Pharaoh . <pharaoh137 at gmail.com> wrote:
> > >It would really help if you'd show us the code of the version of the
> > >driver that you're currently talking about.
> >
> > Hi Clemens...
> >
> > I had sent you the source file having pcm callbacks yesterday, now I
> > have modified the pointer function as follows, I am just giving the
> > pointer function here to avoid duplication, but please let me know in
> > case you want to have look at the entire file.
> >
> >
> > static snd_pcm_uframes_t snd_omap_alsa_pointer(snd_pcm_substream_t
> > *substream)
> > {
> >
> >         struct omap_eac *chip = snd_pcm_substream_chip(substream);
> >         snd_pcm_uframes_t pos = 0;
> >
> >         FN_ENTER;
> >         pos = audio_get_dma_pos(&chip->s[substream->pstr->stream]);
> >         printk("Returning pos = %d\n", pos);
> >         return pos;
> >         FN_EXIT;
> > }
> >
> > static snd_pcm_uframes_t audio_get_dma_pos(struct audio_stream *s)
> > {
> >         snd_pcm_substream_t *substream = s->stream;
> >         snd_pcm_runtime_t *runtime = substream->runtime;
> >         unsigned long flags;
> >         dma_addr_t count;
> >         unsigned long offset;
> >         dma_addr_t src,dest;
> >
> >          if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
> >                 dest = omap_get_dma_dst_pos(s->lch[s->dma_q_head]);
> >                 offset = dest - runtime->dma_addr;
> >                 printk("dest is %u and offset is %u\n",dest,offset);
> >          } else {
> >                 src = omap_get_dma_src_pos(s->lch[s->dma_q_head]);
> >                 offset = src - runtime->dma_addr;
> >                 printk("src is %u and offset is %u\n",dest,offset);
> >          }
> >
> >         return bytes_to_frames(substream->runtime, offset);
> > }
> >
> >
> > And the log is as follows.
> >
> > For the first time.
> >
> >
> > snd_omap_alsa_pointer start
> > src is 3246792928 and offset is 3304194048
> > Returning pos = 20742144
> > Inside snd_pcm_update_hw_ptr_pos, pos is 20742144
> > ALSA sound/core/pcm_lib.c:167: BUG: stream = 0, pos = 0x13c8000,
> > buffer size = 0x4000, period size = 0x800
> > returning pos 20742144
> >
> > I can see things are horribaly wrong here....
> >
> >
> > On 6/26/07, Clemens Ladisch <cladisch at fastmail.net> wrote:
> > > Pharaoh . wrote:
> > > > After rewriting the pointer function
> > >
> > > It would really help if you'd show us the code of the version of the
> > > driver that you're currently talking about.
> > >
> > > > I am not getting the input/output error but I am getting underruns.
> > > > ...
> > > > ALSA sound/core/pcm_lib.c:167: BUG: stream = 0, pos = 0x1150000,
> buffer
> > > size = 0x4000, period size = 0x800
> > >
> > > Here, "pos" is the value returned by your pointer callback.  This value
> > > should have been a frame number somewhere in the buffer, i.e., in the
> > > range 0..0x3fff.  Apparently, the pointer callback doesn't correctly
> > > calculate this value.
> > >
> > > Please remove most printk()s, and add some in the pointer callback to
> > > show both the value that you get from the DMA controller, and the value
> > > that this function returns.
> > >
> > >
> > > Regards,
> > > Clemens
> > >
> >
>