[PATCH] ASoC: arizona: Exit startup early if no runtime

[PATCH] ASoC: arizona: Exit startup early if no runtime

[Charles Keepax]

commit 9b8ef9f6b3fc ("ASoC: dapm: Add startup & shutdown for dai_links")

Added support for calling startup on CODEC to CODEC links, however this
is called with a NULL runtime pointer. There isn't really a sensible way
to pass a valid runtime pointer to a CODEC to CODEC link at the moment,
so we need to make the startup function safe for NULL runtimes.

This patch returns from the Arizona startup function early if there is no
runtime, this is perfectly safe as all the startup function does is set
the PCM constraints for user-space which arn't relevant to a CODEC to
CODEC link anyway.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---
 sound/soc/codecs/arizona.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c
index fb8f188..33143fe 100644
--- a/sound/soc/codecs/arizona.c
+++ b/sound/soc/codecs/arizona.c
@@ -1494,6 +1494,9 @@ static int arizona_startup(struct snd_pcm_substream *substream,
 	const struct snd_pcm_hw_constraint_list *constraint;
 	unsigned int base_rate;
 
+	if (!substream->runtime)
+		return 0;
+
 	switch (dai_priv->clk) {
 	case ARIZONA_CLK_SYSCLK:
 		base_rate = priv->sysclk;
-- 
2.1.4

[PATCH] ASoC: arizona: Exit startup early if no runtime

[Charles Keepax]

commit 9b8ef9f6b3fc ("ASoC: dapm: Add startup & shutdown for dai_links")

Added support for calling startup on CODEC to CODEC links, however this
is called with a NULL runtime pointer. There isn't really a sensible way
to pass a valid runtime pointer to a CODEC to CODEC link at the moment,
so we need to make the startup function safe for NULL runtimes.  This
patch returns from the Arizona startup function early if there is no
runtime.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---

I will fixup the other users as well if everyone is happy
with this approach?

Thanks,
Charles

 sound/soc/codecs/arizona.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c
index 38a73e3..88e2c74 100644
--- a/sound/soc/codecs/arizona.c
+++ b/sound/soc/codecs/arizona.c
@@ -1494,6 +1494,9 @@ static int arizona_startup(struct snd_pcm_substream *substream,
 	const struct snd_pcm_hw_constraint_list *constraint;
 	unsigned int base_rate;
 
+	if (!substream->runtime)
+		return 0;
+
 	switch (dai_priv->clk) {
 	case ARIZONA_CLK_SYSCLK:
 		base_rate = priv->sysclk;
-- 
2.1.4

Re: [PATCH] ASoC: arizona: Exit startup early if no runtime

[Mark Brown]

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On Wed, Dec 23, 2015 at 12:48:01PM +0000, Charles Keepax wrote:
> commit 9b8ef9f6b3fc ("ASoC: dapm: Add startup & shutdown for dai_links")
> 
> Added support for calling startup on CODEC to CODEC links, however this
> is called with a NULL runtime pointer. There isn't really a sensible way
> to pass a valid runtime pointer to a CODEC to CODEC link at the moment,
> so we need to make the startup function safe for NULL runtimes.  This
> patch returns from the Arizona startup function early if there is no
> runtime.

We need a bit more here about why it's safe to just skip this code - it
is actually safe since we're just setting constraints for userspace but
that's not something the reader can tell without looking for more
context.

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Re: [PATCH] ASoC: arizona: Exit startup early if no runtime

[Charles Keepax]

On Thu, Dec 24, 2015 at 07:41:05PM +0000, Mark Brown wrote:
> On Wed, Dec 23, 2015 at 12:48:01PM +0000, Charles Keepax wrote:
> > commit 9b8ef9f6b3fc ("ASoC: dapm: Add startup & shutdown for dai_links")
> > 
> > Added support for calling startup on CODEC to CODEC links, however this
> > is called with a NULL runtime pointer. There isn't really a sensible way
> > to pass a valid runtime pointer to a CODEC to CODEC link at the moment,
> > so we need to make the startup function safe for NULL runtimes.  This
> > patch returns from the Arizona startup function early if there is no
> > runtime.
> 
> We need a bit more here about why it's safe to just skip this code - it
> is actually safe since we're just setting constraints for userspace but
> that's not something the reader can tell without looking for more
> context.

Yeah no problem I will respin and send out a new version today.

Thanks,
Charles