On Thu, Nov 13, 2008 at 03:57:08PM +0100, christian pellegrin wrote: > during the porting the uda134x driver to the git devel branch of ALSA > SOC I noticed a possible problem in s3c24xx-pcm.c. s3c24xx_pcm_enqueue > gained a new parameter that specifies the maximum number of periods > that can be enqueued. In s3c24xx_pcm_prepare, which is called on > play/capture start, this is limited to 1. Unfortunately on the 2410 > the result of this change is that the DMA is stopped because the > autoload of the next DMA descriptor doesn't work. I copied a log at > the end of this email. Look for DMT==00 after the irq signaling the > end of the first period and the subsequent fail of DMA loading since > the channel is stopped. CCing in Dave Anders who wrote that patch (though the problem it fixes was reported previously). I can't help but think that this ought to be being dealt with within the DMA code, it all feels rather fragile. > Now I fixed with: > --- a/sound/soc/s3c24xx/s3c24xx-pcm.c > +++ b/sound/soc/s3c24xx/s3c24xx-pcm.c > @@ -253,7 +253,7 @@ static int s3c24xx_pcm_prepare(struct > snd_pcm_substream *substream) > prtd->dma_pos = prtd->dma_start; > > /* enqueue dma buffers */ > - s3c24xx_pcm_enqueue(substream, 1); > + s3c24xx_pcm_enqueue(substream, 2); > > return ret; > } > > but this really could be "playing with DMA" since I'm not sure why > there is a 1 (since min_period is 2 I would guess 2 is the right > value). Anyway with this change play and capture work well. See the commit log - the underlying DMA code restricts the number of buffers that can be queued up prior to the start of DMA. > > # /opt/arm/alsa/bin/aplay /mp3z/prova.wav > s3c24xx-pcm: Entered s3c24xx_pcm_open > s3c24xx_uda134x_startup 0 > 31250, 132031, 66015, 44010, 33007, 26406, 22005, 18861, 16503, > 14670, 13203, 12002, 11002, 10156, 9430, 8802, 8251, 7766, 7335, 6949, > 6601, 6287, 6001, 5740, 5501, 5281, 5078, 4890, 4715, 4552, 4401, > 4259, 4125, 46875, 198046, 99023, 66015, 49511, 39609, 33007, 28292, > 24755, 22005, 19804, 18004, 16503, 15234, 14146, 13203, 12377, 11649, > 11002, 10423, 9902, 9430, 9002, 8610, 8251, 7921, 7617, 7335, 7073, > 6829, 6601, 6388, 6188, > Playing WAVE '/mp3z/prova.wav' : Signed 16 bit Little Endian, Rate 8000 Hz, Mono > s3c24xx_uda134x_hw_params desired rate 8000, 58 > s3c24xx_uda134x_hw_params will use: 256FS PCLK 24 sysclk 2048000 err 79 > uda134x_set_dai_fmt fmt: 00003000 > s3c24xx-i2s: Entered s3c24xx_i2s_set_fmt > s3c24xx-i2s: hw_params r: IISMOD: 9 > s3c24xx-i2s: hw_params w: IISMOD: 9 > s3c24xx-i2s: Entered s3c24xx_i2s_set_sysclk > s3c24xx-i2s: Entered s3c24xx_i2s_set_clkdiv > s3c24xx-i2s: Entered s3c24xx_i2s_set_clkdiv > s3c24xx-i2s: Entered s3c24xx_i2s_set_clkdiv > uda134x_set_dai_sysclk clk_id: 0, freq: 2048000, dir: 1 > uda134x_hw_params sysclk: 2048000, rate:8000 > uda134x_hw_params dai_fmt: 12288, params_format:2 > uda134x_write reg: 08, value:20 > s3c24xx-i2s: Entered s3c24xx_i2s_hw_params > s3c24xx-i2s: hw_params r: IISMOD: 9 > s3c24xx-i2s: hw_params w: IISMOD: 9 > s3c24xx-pcm: Entered s3c24xx_pcm_hw_params > s3c24xx-pcm: params bf0673f4, client bf067404, channel 10 > dma10: s3c2410_request_dma: client=I2S PCM Stereo out, dev=00000000 > mapped channel 10 to 2 > dma2: s3c2410_dma_request:755: ls=0, cur=c326b020, 00000000 c326b020 > dma2: s3c2410_dma_request:755: DCSRC=332a05c4, DISRC=332a0000, > DSTAT=00000000 DMT=04, DCON=a0d00000 > dma10: s3c2410_dma_request : requesting irq 35 > s3c2410_dma_request: channel initialised, c044fdd4 > s3c2410_dma_set_buffdone_fn: chan=c044fdd4, callback rtn=bf05d108 > s3c24xx-pcm: Entered s3c24xx_pcm_mmap > s3c24xx-pcm: Entered s3c24xx_pcm_prepare > s3c2410_dma_devconfig: source=1, hwcfg=00000003, devaddr=55000010 > s3c2410_dma_devconfig: mem source, devaddr=55000010, hwcfg=3 > s3c2410_dma_config: chan=10, xfer_unit=2, dcon=80000000 > s3c2410_dma_config: Initial dcon is 80000000 > s3c2410_dma_config: New dcon is 80000000 > s3c2410_dma_config: dcon now a0900000 > s3c2410_dma_flush: chan c044fdd4 (2) > dma2: s3c2410_dma_flush:912: ls=0, cur=c326b020, 00000000 c326b020 > dma2: s3c2410_dma_flush:912: DCSRC=332a05c4, DISRC=332a0000, > DSTAT=00000000 DMT=04, DCON=a0d00000 > s3c2410_dma_flush: free buffer c326b020, next 00000000 > s3c24xx-pcm: Entered s3c24xx_audio_buffdone > dma2: s3c2410_dma_flush:939: DCSRC=332a05c4, DISRC=332a0000, > DSTAT=00000000 DMT=04, DCON=a0d00000 > dma2: s3c2410_dma_flush:954: DCSRC=332a05c4, DISRC=332a0000, > DSTAT=00000000 DMT=04, DCON=a0d00000 > s3c24xx-pcm: Entered s3c24xx_pcm_enqueue dma_max 1 > s3c24xx-pcm: dma_loaded: 0 pos: 332a0000 len: 4096 dma_max: 1 dma_end: 332a3e80 > s3c2410_dma_enqueue: id=c31fa300, data=332a0000, size=4096 > s3c2410_dma_enqueue: buffer c326b020 queued onto empty channel > s3c24xx-pcm: ret 0 period 4096 > uda134x_mute mute: 0 > uda134x_write reg: 0C, value:80 > s3c24xx-pcm: Entered s3c24xx_pcm_trigger > s3c2410_start_dma: channel=2 > s3c2410_chan_loadbuffer: loading buff c326b020 (0x332a0000,0x001000) > load_state is none, checking for noreload (next=00000000) > dma2: s3c2410_dma_start:366: ls=1, cur=c326b020, 00000000 c326b020 > dma2: s3c2410_dma_start:366: DCSRC=332a05c4, DISRC=332a0000, > DSTAT=00000000 DMT=04, DCON=a0d00800 > dma2: 00000002 to DMASKTRIG > dma2: s3c2410_dma_start:394: ls=1, cur=c326b020, 00000000 c326b020 > dma2: s3c2410_dma_start:394: DCSRC=332a05c4, DISRC=332a0000, > DSTAT=00000000 DMT=02, DCON=a0d00800 > dma2: s3c2410_dma_started:967: ls=1, cur=c326b020, 00000000 c326b020 > dma2: s3c2410_dma_started:967: DCSRC=332a05c4, DISRC=332a0000, > DSTAT=00000000 DMT=02, DCON=a0d00800 > s3c24xx-i2s: Entered s3c24xx_i2s_trigger > s3c24xx-i2s: Entered s3c24xx_snd_is_clkmaster > s3c24xx-i2s: Entered s3c24xx_snd_txctrl > s3c24xx-i2s: r: IISCON: 10f IISMOD: 9 IISFCON: 0 > s3c24xx-i2s: w: IISCON: 127 IISMOD: 89 IISFCON: a000 > s3c24xx-pcm: Entered s3c24xx_pcm_pointer > s3c24xx-pcm: Pointer 332a0158 55000010 > dma2: s3c2410_dma_irq:608: ls=1, cur=c326b020, 00000000 c326b020 > dma2: s3c2410_dma_irq:608: DCSRC=332a1000, DISRC=332a0000, > DSTAT=00000000 DMT=00, DCON=a0d00800 > s3c24xx-pcm: Entered s3c24xx_audio_buffdone > s3c24xx-pcm: Entered s3c24xx_pcm_pointer > s3c24xx-pcm: Pointer 332a1000 55000010 > s3c24xx-pcm: Entered s3c24xx_pcm_enqueue dma_max 0 > s3c24xx-pcm: dma_loaded: 0 pos: 332a1000 len: 4096 dma_max: 2 dma_end: 332a3e80 > s3c2410_dma_enqueue: id=c31fa300, data=332a1000, size=4096 > s3c2410_dma_enqueue: buffer c326b040 queued onto empty channel > s3c2410_chan_loadbuffer: loading buff c326b040 (0x332a1000,0x001000) > load_state is none, checking for noreload (next=00000000) > s3c24xx-pcm: ret 0 period 4096 > s3c24xx-pcm: dma_loaded: 1 pos: 332a2000 len: 4096 dma_max: 2 dma_end: 332a3e80 > s3c2410_dma_enqueue: id=c31fa300, data=332a2000, size=4096 > dma2: s3c2410_dma_enqueue: buffer c326b000 queued onto non-empty channel > dma2: loadbuffer:timeout loading buffer > dma2: s3c2410_dma_enqueue:517: ls=1, cur=c326b040, c326b000 c326b000 > dma2: s3c2410_dma_enqueue:517: DCSRC=332a1000, DISRC=332a1000, > DSTAT=00000000 DMT=00, DCON=a0d00800 > s3c24xx-pcm: ret -22 period 4096 > dma2: timeout waiting for load (s3c2410_dma_irq) > s3c24xx-pcm: Entered s3c24xx_pcm_pointer > s3c24xx-pcm: Pointer 332a1000 55000010 > s3c24xx-pcm: Entered s3c24xx_pcm_pointer > s3c24xx-pcm: Pointer 332a1000 55000010 > ^CAborted by signals3c24xx-pcm: Entered s3c24xx_pcm_trigger > s3c2410_dma_dostop: > dma2: s3c2410_dma_dostop:857: ls=1, cur=c326b040, c326b000 c326b000 > dma2: s3c2410_dma_dostop:857: DCSRC=332a1000, DISRC=332a1000, > DSTAT=00000000 DMT=00, DCON=a0d00800 > s3c24xx-i2s: Entered s3c24xx_i2s_trigger > s3c24xx-i2s: Entered s3c24xx_snd_txctrl > s3c24xx-i2s: r: IISCON: 127 IISMOD: 89 IISFCON: a000 > > > -- > Christian Pellegrin, see http://www.evolware.org/chri/ > "Real Programmers don't play tennis, or any other sport which requires > you to change clothes. Mountain climbing is OK, and Real Programmers > wear their climbing boots to work in case a mountain should suddenly > spring up in the middle of the computer room." > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@xxxxxxxxxxxxxxxx > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel > -- "You grabbed my hand and we fell into it, like a daydream - or a fever." _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
