[PATCH] ASoC: tegra: fix maxburst settings in dmaengine code

[PATCH] ASoC: tegra: fix maxburst settings in dmaengine code

[Stephen Warren]

From: Stephen Warren <swarren@nvidia.com>

The I2S controllers are programmed with an "attention" level of 4 DWORDs.
This must match the configuration passed to the DMA driver, so that when
they burst in data, they don't overflow the available FIFO space. Also,
the burst size is relevant to the destination for playback, and source
for capture, not vice-versa as originally written.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
Mark, I'd like to take this patch through the Tegra tree, since it's a
dependency for the series that converts Tegra to dmaengine. Thanks.

 sound/soc/tegra/tegra_pcm.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/soc/tegra/tegra_pcm.c b/sound/soc/tegra/tegra_pcm.c
index 5658bce..8d6900c 100644
--- a/sound/soc/tegra/tegra_pcm.c
+++ b/sound/soc/tegra/tegra_pcm.c
@@ -334,11 +334,11 @@ static int tegra_pcm_hw_params(struct snd_pcm_substream *substream,
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 		slave_config.dst_addr = dmap->addr;
-		slave_config.src_maxburst = 0;
+		slave_config.dst_maxburst = 4;
 	} else {
 		slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 		slave_config.src_addr = dmap->addr;
-		slave_config.dst_maxburst = 0;
+		slave_config.src_maxburst = 4;
 	}
 	slave_config.slave_id = dmap->req_sel;
 
-- 
1.7.0.4

Re: [PATCH] ASoC: tegra: fix maxburst settings in dmaengine code

[Mark Brown]

On Thu, Sep 06, 2012 at 05:47:33PM -0600, Stephen Warren wrote:

> Mark, I'd like to take this patch through the Tegra tree, since it's a
> dependency for the series that converts Tegra to dmaengine. Thanks.

Since it's a fix I was going to send it as a patch for 3.6 so that
shouldn't be an issue?

Re: [PATCH] ASoC: tegra: fix maxburst settings in dmaengine code

[Stephen Warren]

On 09/06/2012 07:00 PM, Mark Brown wrote:
> On Thu, Sep 06, 2012 at 05:47:33PM -0600, Stephen Warren wrote:
> 
>> Mark, I'd like to take this patch through the Tegra tree, since it's a
>> dependency for the series that converts Tegra to dmaengine. Thanks.
> 
> Since it's a fix I was going to send it as a patch for 3.6 so that
> shouldn't be an issue?

Oh right, that makes sense too, thanks.

Re: [PATCH] ASoC: tegra: fix maxburst settings in dmaengine code

[Stephen Warren]

On 09/06/2012 07:36 PM, Stephen Warren wrote:
> On 09/06/2012 07:00 PM, Mark Brown wrote:
>> On Thu, Sep 06, 2012 at 05:47:33PM -0600, Stephen Warren wrote:
>>
>>> Mark, I'd like to take this patch through the Tegra tree, since it's a
>>> dependency for the series that converts Tegra to dmaengine. Thanks.
>>
>> Since it's a fix I was going to send it as a patch for 3.6 so that
>> shouldn't be an issue?
> 
> Oh right, that makes sense too, thanks.

Mark,

This patch shows up in your ASoC for-next branch, but not in your
for-3.6 or for-3.7 branches. I think gitk is telling me that you simply
forgot to push your latest for-3.6 branch to kernel.org when you pushed
your updated for-next.

Anyway, since this patch didn't make 3.6-rc5, it is difficult for me to
use as a baseline for any branches destined for 3.7, since I'm supposed
to send my pull requests to arm-soc before 3.6-rc6 is released, yet if
this patch goes into 3.6, it won't be there until 3.6-rc6 at the earliest.

I'm not sure how best to resolve this; is it possible for me to take the
patch through the Tegra tree instead, as I originally intended?

Re: [PATCH] ASoC: tegra: fix maxburst settings in dmaengine code

[Mark Brown]

On Mon, Sep 10, 2012 at 12:03:31PM -0600, Stephen Warren wrote:

> Anyway, since this patch didn't make 3.6-rc5, it is difficult for me to
> use as a baseline for any branches destined for 3.7, since I'm supposed
> to send my pull requests to arm-soc before 3.6-rc6 is released, yet if
> this patch goes into 3.6, it won't be there until 3.6-rc6 at the earliest.

> I'm not sure how best to resolve this; is it possible for me to take the
> patch through the Tegra tree instead, as I originally intended?

Just merge the pull request in.  I should send something out
on Thursday I expect, though no guarantees about -rc6.  It doesn't seem
sensible to not merge the fix.

Or bend the rules for arm-soc by putting it in your own -next branch and
then rebasing before it gets pulled into arm-soc.  This would seem a
sensible thing in general given arm-soc has this sort of model, it'd
avoid what is essentially an extended merge window for arm-soc but still
give things exposure in -next before they hit arm-soc itself.

Re: [PATCH] ASoC: tegra: fix maxburst settings in dmaengine code

[Mark Brown]

On Thu, Sep 06, 2012 at 05:47:33PM -0600, Stephen Warren wrote:
> From: Stephen Warren <swarren@nvidia.com>
> 
> The I2S controllers are programmed with an "attention" level of 4 DWORDs.
> This must match the configuration passed to the DMA driver, so that when
> they burst in data, they don't overflow the available FIFO space. Also,
> the burst size is relevant to the destination for playback, and source
> for capture, not vice-versa as originally written.

Applied, thanks.