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 <[email protected]> for detailed problem > analysis and Peter Ujfalusi <[email protected]> for info about DMA > request line behavior differences between the OMAP generations. > > Reported-and-tested-by: Janusz Krzysztofik <[email protected]> > Signed-off-by: Jarkko Nikula <[email protected]> > Cc: Mark Brown <[email protected]> > Cc: Tony Lindgren <[email protected]> > --- > 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; -- Péter -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
