[alsa-devel] sound/pci/au88x0/au88x0_core.c:2464 vortex_interrupt() warn: if();

[Raymond Yau]

2012-10-23 下午10:35 於 "Takashi Iwai" <tiwai at suse.de> 寫道：
>
> At Tue, 23 Oct 2012 22:16:42 +0800,
> Fengguang Wu wrote:
> >
> > Hi,
> >
> > smatch warns about a weird "if();" in sound/pci/au88x0/au88x0_core.c
> > Any ideas to fix it?
> >
> >         2461 #ifndef CHIP_AU8810
> >         2462                 for (i = 0; i < NR_WT; i++) {
> >         2463                         if (vortex->dma_wt[i].fifo_status
== FIFO_START) {
> > ==>     2464                                 if
(vortex_wtdma_bufshift(vortex, i)) ;
> >         2465                                 spin_unlock(&vortex->lock);
> >         2466
snd_pcm_period_elapsed(vortex->dma_wt[i].
> >         2467
 substream);
> >         2468                                 spin_lock(&vortex->lock);
> >         2469                         }
> >         2470                 }
> >         2471 #endif
>
> A quick fix is below, but I'm not 100% sure about it yet.
> Let's see.

using aplay with  VORTEX_PCM_WT , only a very low high frequency signal is
heard  and after 10 seconds

aplay: pcm_write:1702: write error: Input/output error

refer to the patent 6167465 the wavetable DMA channels operate slightly
different from the non-wavetable DMA channels

it seem that the driver still cannot send the increment wavetable pointer
signal and the increment count signal , thus fifo controller does not reach
the trigger level to request for a dma transfer

may need some code to use the sound card's timer interrupt to send
increment wavetable pointer signal to provide pitching by perform sample
rate conversion on the data through interpolation and looping

BTW au88x0 still missing channel map

/* pre-allocation of Scatter-Gather buffers */

snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV_SG,
      snd_dma_pci_data(chip->pci_dev),
      0x10000, 0x10000);

+if (VORTEX_PCM_TYPE(pcm) == VORTEX_PCM_ADB) {
+       err = snd_pcm_add_chmap_ctls(pcm, SNDRV_PCM_STREAM_PLAYBACK,
+                                    snd_pcm_std_chmaps, 4, 0, NULL);
+       if (err < 0)
+               return err;
+  }
if (VORTEX_PCM_TYPE(pcm) == VORTEX_PCM_SPDIF) {

http://git.alsa-project.org/?p=alsa-lib.git;a=commitdiff;h=3fc13d6f5b08edee49b106cd711d51bf3aef6ab7;hp=662f79d4ec6b52bbaab28d5a9b60cc8bcdf042f9

how about capture stream since test/chmap can open capture stream ?

case 's':
                       if (*optarg == 'c' || *optarg == 'C')
                               stream = SND_PCM_STREAM_CAPTURE;
                       else
                               stream = SND_PCM_STREAM_PLAYBACK;
                       break;

do VORTEX_PCM_A3D need a mono channel map since device 2 only support mono
playback with spatalization to stereo output ?

how about the mono channel map of emu10k1 and trident ?
>
>
> thanks,
>
> Takashi
>
> ---
> diff --git a/sound/pci/au88x0/au88x0_core.c
b/sound/pci/au88x0/au88x0_core.c
> index 525f881..3fe3dbe 100644
> --- a/sound/pci/au88x0/au88x0_core.c
> +++ b/sound/pci/au88x0/au88x0_core.c
> @@ -2461,7 +2461,8 @@ static irqreturn_t vortex_interrupt(int irq, void
*dev_id)
>  #ifndef CHIP_AU8810
>                 for (i = 0; i < NR_WT; i++) {
>                         if (vortex->dma_wt[i].fifo_status == FIFO_START) {
> -                               if (vortex_wtdma_bufshift(vortex, i)) ;
> +                               if (!vortex_wtdma_bufshift(vortex, i))
> +                                       continue;
>                                 spin_unlock(&vortex->lock);
>                                 snd_pcm_period_elapsed(vortex->dma_wt[i].
>                                                        substream);