On Sun, Dec 21, 2008 at 9:22 AM, naveenkrishna. ch <
naveenkrishna.ch@xxxxxxxxx> wrote:
> Hi ALSA SOC,
>
> I am using a OMAP3 + TWL4030 combination with ASoC
>
> in the sound/soc/omap/omap-pcm.c
> DMA channels are being freed after unlinking in the omap_pcm_hw_free
> function
>
> Which is causing a crash during applications
> So, stopping the DMA channels before unlinking resolves the issue.
>
> here is the patch that solves the issue
>
> diff --git a/sound/soc/omap/omap-pcm.c b/sound/soc/omap/omap-pcm.c
> index e9084fd..679e384 100644
> --- a/sound/soc/omap/omap-pcm.c
> +++ b/sound/soc/omap/omap-pcm.c
> @@ -116,6 +116,7 @@ static int omap_pcm_hw_free(struct snd_pcm_substream
> *substream)
> if (prtd->dma_data == NULL)
> return 0;
>
> + omap_stop_dma(prtd->dma_ch);
> if (!cpu_is_omap1510())
> omap_dma_unlink_lch(prtd->dma_ch, prtd->dma_ch);
> omap_free_dma(prtd->dma_ch);
>
>
> Is this ok or is there any better way out
> --
>
This looks a bit familiar, I hope so. Is this from linux-omap, mainline or
in-house kernel?
There were similar issues fixed by following two patches in linux-omap.
Second one is not yet in mainline, have to confirm with Tony has he queued
it now.
commit 66c23551b1b774e2be3c7bdf91c0ebf2c7a3519e
Author: Jarkko Nikula <jarkko.nikula@xxxxxxxxx>
Date: Tue May 13 13:26:03 2008 +0300
ARM: OMAP: DMA: Don't mark channel active in omap_enable_channel_irq
Channel should be marked active only when DMA is really started.
Otherwise
just omap_request_dma, omap_dma_link_lch and omap_dma_unlink_lch will
cause
incorrect dump_stack().
commit 55502f74b56f609a84d8919b9b29390b2e0147ff
Author: Jarkko Nikula <jarkko.nikula@xxxxxxxxx>
Date: Mon Aug 18 12:28:22 2008 +0300
ARM: OMAP: DMA: Fix uninitialized channel flags
This has similar symptoms than 66c23551b1b774e2be3c7bdf91c0ebf2c7a3519e
where just omap_request_dma, omap_dma_link_lch and omap_dma_unlink_lch
can cause incorrect dump_stack(). Here it can happen if channel has been
used before and the channel flags variable holds old status.
Signed-off-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
Then it's worth to verify also this very recent fix. This is already in
mainline and will flow into linux-omap when Tony does the pull.
commit 19b3f31609dc8be3a56c78dcb7da723f10f7009c
Author: Stanley Miao <stanley.miao@xxxxxxxxxxxxx>
Date: Fri Dec 19 22:08:22 2008 +0800
ALSA: Fix a Oops bug in omap soc driver.
There will be a Oops or frequent underrun messages when playing music
with
omap soc driver, this is because a data region is incorretly sized,
other da
region will be overwriten when writing to this data region.
Jarkko
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