Messages in this thread Patch in this message | | | From | Peter Ujfalusi <> | Subject | Re: [alsa-devel] [PATCH][2.6.31-rc5] ARM: OMAP: McBSP: Fix ASoC on OMAP1510 by fixing API of omap_mcbsp_start/stop | Date | Fri, 7 Aug 2009 11:30:54 +0300 |
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On Friday 07 August 2009 09:59:47 ext Jarkko Nikula wrote: > Simultaneous audio playback and capture on OMAP1510 can cause that second > stream is stalled if there is enough delay between startup of the audio > streams. > > Current implementation of the omap_mcbsp_start is starting both transmitter > and receiver at the same time and it is called only for firstly started > audio stream from the OMAP McBSP based ASoC DAI driver. > > Since DMA request lines on OMAP1510 are edge sensitive, the DMA request is > missed if there is no DMA transfer set up at that time when the first word > after McBSP startup is transmitted. The problem hasn't noted before since > later OMAPs are using level sensitive DMA request lines. > > Fix the problem by changing API of omap_mcbsp_start and omap_mcbsp_stop by > allowing to start and stop individually McBSP transmitter and receiver > logics. Then call those functions individually for both audio playback > and capture streams. This ensures that DMA transfer is setup before > transmitter or receiver is started.
Looks nice, but I would have done it a bit differently...
> > Thanks to Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> for detailed problem > analysis and Peter Ujfalusi <peter.ujfalusi@nokia.com> for info about DMA > request line behavior differences between the OMAP generations. > > Reported-and-tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> > Signed-off-by: Jarkko Nikula <jhnikula@gmail.com> > Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> > Cc: Tony Lindgren <tony@atomide.com> > --- > arch/arm/plat-omap/include/mach/mcbsp.h | 4 +- > arch/arm/plat-omap/mcbsp.c | 50 > +++++++++++++++++++----------- sound/soc/omap/omap-mcbsp.c | > 10 +++--- > 3 files changed, 39 insertions(+), 25 deletions(-) > > diff --git a/arch/arm/plat-omap/include/mach/mcbsp.h > b/arch/arm/plat-omap/include/mach/mcbsp.h index bb154ea..57249bb 100644 > --- a/arch/arm/plat-omap/include/mach/mcbsp.h > +++ b/arch/arm/plat-omap/include/mach/mcbsp.h > @@ -387,8 +387,8 @@ void omap_mcbsp_register_board_cfg(struct > omap_mcbsp_platform_data *config, void omap_mcbsp_config(unsigned int id, > const struct omap_mcbsp_reg_cfg * config); int omap_mcbsp_request(unsigned > int id); > void omap_mcbsp_free(unsigned int id); > -void omap_mcbsp_start(unsigned int id); > -void omap_mcbsp_stop(unsigned int id); > +void omap_mcbsp_start(unsigned int id, int tx, int rx); > +void omap_mcbsp_stop(unsigned int id, int tx, int rx);
void omap_mcbsp_start(unsigned int id, int dir); void omap_mcbsp_stop(unsigned int id, int dir);
> void omap_mcbsp_xmit_word(unsigned int id, u32 word); > u32 omap_mcbsp_recv_word(unsigned int id); > > diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c > index efa0e01..a3d2313 100644 > --- a/arch/arm/plat-omap/mcbsp.c > +++ b/arch/arm/plat-omap/mcbsp.c > @@ -328,14 +328,15 @@ void omap_mcbsp_free(unsigned int id) > EXPORT_SYMBOL(omap_mcbsp_free); > > /* > - * Here we start the McBSP, by enabling the sample > - * generator, both transmitter and receivers, > - * and the frame sync. > + * Here we start the McBSP, by enabling transmitter, receiver or both. > + * If no transmitter or receiver is active prior calling, then sample-rate > + * generator and frame sync are started.
* dir == 0: tx * dir == 1: rx
> */ > -void omap_mcbsp_start(unsigned int id) > +void omap_mcbsp_start(unsigned int id, int tx, int rx)
void omap_mcbsp_start(unsigned int id, int dir)
> { > struct omap_mcbsp *mcbsp; > void __iomem *io_base; > + int idle; > u16 w;
...
> /* Enable transmitter and receiver */ > w = OMAP_MCBSP_READ(io_base, SPCR2); > - OMAP_MCBSP_WRITE(io_base, SPCR2, w | 1); > + OMAP_MCBSP_WRITE(io_base, SPCR2, w | (tx & 1)); > > w = OMAP_MCBSP_READ(io_base, SPCR1); > - OMAP_MCBSP_WRITE(io_base, SPCR1, w | 1); > + OMAP_MCBSP_WRITE(io_base, SPCR1, w | (rx & 1));
if (dir) { /* RX: Enable receiver */ w = OMAP_MCBSP_READ(io_base, SPCR1); OMAP_MCBSP_WRITE(io_base, SPCR1, w | 1); } else { /* TX: Enable transmitter */ w = OMAP_MCBSP_READ(io_base, SPCR2); OMAP_MCBSP_WRITE(io_base, SPCR2, w | 1); }
> udelay(100);
...
> -void omap_mcbsp_stop(unsigned int id) > +void omap_mcbsp_stop(unsigned int id, int tx, int rx)
void omap_mcbsp_stop(unsigned int id, int dir)
> { > struct omap_mcbsp *mcbsp; > void __iomem *io_base; > + int idle; > u16 w; > > if (!omap_mcbsp_check_valid_id(id)) { > @@ -386,15 +395,20 @@ void omap_mcbsp_stop(unsigned int id) > > /* Reset transmitter */ > w = OMAP_MCBSP_READ(io_base, SPCR2); > - OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1)); > + OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(tx & 1)); > > /* Reset receiver */ > w = OMAP_MCBSP_READ(io_base, SPCR1); > - OMAP_MCBSP_WRITE(io_base, SPCR1, w & ~(1)); > + OMAP_MCBSP_WRITE(io_base, SPCR1, w & ~(rx & 1));
if (dir) { /* RX: Reset receiver */ w = OMAP_MCBSP_READ(io_base, SPCR1); OMAP_MCBSP_WRITE(io_base, SPCR1, w | ~(1)); } else { /* TX: Reset transmitter */ w = OMAP_MCBSP_READ(io_base, SPCR2); OMAP_MCBSP_WRITE(io_base, SPCR2, w | ~(1)); }
> - /* Reset the sample rate generator */ > - w = OMAP_MCBSP_READ(io_base, SPCR2); > - OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1 << 6)); > + idle = !((OMAP_MCBSP_READ(io_base, SPCR2) | > + OMAP_MCBSP_READ(io_base, SPCR1)) & 1); > + > + if (idle) { > + /* Reset the sample rate generator */ > + w = OMAP_MCBSP_READ(io_base, SPCR2); > + OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1 << 6)); > + } > } > EXPORT_SYMBOL(omap_mcbsp_stop); > > diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c > index a5d46a7..6a837ff 100644 > --- a/sound/soc/omap/omap-mcbsp.c > +++ b/sound/soc/omap/omap-mcbsp.c > @@ -183,21 +183,21 @@ static int omap_mcbsp_dai_trigger(struct > snd_pcm_substream *substream, int cmd, struct snd_soc_pcm_runtime *rtd = > substream->private_data; > struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai; > struct omap_mcbsp_data *mcbsp_data = to_mcbsp(cpu_dai->private_data); > - int err = 0; > + int err = 0, play = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
no need for this change.
> > switch (cmd) { > case SNDRV_PCM_TRIGGER_START: > case SNDRV_PCM_TRIGGER_RESUME: > case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: > - if (!mcbsp_data->active++) > - omap_mcbsp_start(mcbsp_data->bus_id); > + mcbsp_data->active++; > + omap_mcbsp_start(mcbsp_data->bus_id, play, !play);
omap_mcbsp_start(mcbsp_data->bus_id, substream->stream);
> break; > > case SNDRV_PCM_TRIGGER_STOP: > case SNDRV_PCM_TRIGGER_SUSPEND: > case SNDRV_PCM_TRIGGER_PAUSE_PUSH: > - if (!--mcbsp_data->active) > - omap_mcbsp_stop(mcbsp_data->bus_id); > + omap_mcbsp_stop(mcbsp_data->bus_id, play, !play);
omap_mcbsp_stop(mcbsp_data->bus_id, substream->stream);
> + mcbsp_data->active--; > break; > default: > err = -EINVAL;
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