[alsa-devel] [PATCH v2 01/11] ASoC: samsung: s3c2412: Handle return value of clk_prepare_enable.
clk_prepare_enable() can fail here and we must check its return value.
Signed-off-by: Arvind Yadav arvind.yadav.cs@gmail.com --- Chnage in v2 : Error handling for things done in s3c_i2sv2_probe().
sound/soc/samsung/s3c2412-i2s.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/sound/soc/samsung/s3c2412-i2s.c b/sound/soc/samsung/s3c2412-i2s.c index 0a47182..0b96927 100644 --- a/sound/soc/samsung/s3c2412-i2s.c +++ b/sound/soc/samsung/s3c2412-i2s.c @@ -65,13 +65,16 @@ static int s3c2412_i2s_probe(struct snd_soc_dai *dai) s3c2412_i2s.iis_cclk = devm_clk_get(dai->dev, "i2sclk"); if (IS_ERR(s3c2412_i2s.iis_cclk)) { pr_err("failed to get i2sclk clock\n"); - return PTR_ERR(s3c2412_i2s.iis_cclk); + ret = PTR_ERR(s3c2412_i2s.iis_cclk); + goto err; }
/* Set MPLL as the source for IIS CLK */
clk_set_parent(s3c2412_i2s.iis_cclk, clk_get(NULL, "mpll")); - clk_prepare_enable(s3c2412_i2s.iis_cclk); + ret = clk_prepare_enable(s3c2412_i2s.iis_cclk); + if (ret) + goto err;
s3c2412_i2s.iis_cclk = s3c2412_i2s.iis_pclk;
@@ -80,6 +83,11 @@ static int s3c2412_i2s_probe(struct snd_soc_dai *dai) S3C_GPIO_PULL_NONE);
return 0; + +err: + clk_disable(s3c2412_i2s.iis_pclk); + clk_put(s3c2412_i2s.iis_pclk); + return ret; }
static int s3c2412_i2s_remove(struct snd_soc_dai *dai)
On Wed, Jul 26, 2017 at 11:15:25AM +0530, Arvind Yadav wrote:
--- a/sound/soc/samsung/s3c2412-i2s.c +++ b/sound/soc/samsung/s3c2412-i2s.c @@ -65,13 +65,16 @@ static int s3c2412_i2s_probe(struct snd_soc_dai *dai) s3c2412_i2s.iis_cclk = devm_clk_get(dai->dev, "i2sclk"); if (IS_ERR(s3c2412_i2s.iis_cclk)) { pr_err("failed to get i2sclk clock\n");
return PTR_ERR(s3c2412_i2s.iis_cclk);
ret = PTR_ERR(s3c2412_i2s.iis_cclk);goto err;
Why are we making this unrelated change? None of the error handling we jump to is relevant if this fails...
/* Set MPLL as the source for IIS CLK */
clk_set_parent(s3c2412_i2s.iis_cclk, clk_get(NULL, "mpll"));
- clk_prepare_enable(s3c2412_i2s.iis_cclk);
ret = clk_prepare_enable(s3c2412_i2s.iis_cclk);
if (ret)
goto err;s3c2412_i2s.iis_cclk = s3c2412_i2s.iis_pclk;
@@ -80,6 +83,11 @@ static int s3c2412_i2s_probe(struct snd_soc_dai *dai) S3C_GPIO_PULL_NONE);
return 0;
+err:
- clk_disable(s3c2412_i2s.iis_pclk);
This will disable the clock if we failed to enable it which is clearly not correct. It's also matching a clk_prepare_enable() with a clk_disable() which is going to leave an unbalanced prepare.
Hi,
On Wednesday 26 July 2017 04:58 PM, Mark Brown wrote:
On Wed, Jul 26, 2017 at 11:15:25AM +0530, Arvind Yadav wrote:
--- a/sound/soc/samsung/s3c2412-i2s.c +++ b/sound/soc/samsung/s3c2412-i2s.c @@ -65,13 +65,16 @@ static int s3c2412_i2s_probe(struct snd_soc_dai *dai) s3c2412_i2s.iis_cclk = devm_clk_get(dai->dev, "i2sclk"); if (IS_ERR(s3c2412_i2s.iis_cclk)) { pr_err("failed to get i2sclk clock\n");
return PTR_ERR(s3c2412_i2s.iis_cclk);
ret = PTR_ERR(s3c2412_i2s.iis_cclk);goto err;Why are we making this unrelated change? None of the error handling we jump to is relevant if this fails...
3c_i2sv2_probe is enabling "iis" clock. If devm_clk_get(, "i2sclk") fails. we need to disable and free the clock "iis" .
/* Set MPLL as the source for IIS CLK */
clk_set_parent(s3c2412_i2s.iis_cclk, clk_get(NULL, "mpll"));
- clk_prepare_enable(s3c2412_i2s.iis_cclk);
ret = clk_prepare_enable(s3c2412_i2s.iis_cclk);
if (ret)
goto err;s3c2412_i2s.iis_cclk = s3c2412_i2s.iis_pclk;
@@ -80,6 +83,11 @@ static int s3c2412_i2s_probe(struct snd_soc_dai *dai) S3C_GPIO_PULL_NONE);
return 0;
+err:
- clk_disable(s3c2412_i2s.iis_pclk);
This will disable the clock if we failed to enable it which is clearly not correct. It's also matching a clk_prepare_enable() with a clk_disable() which is going to leave an unbalanced prepare.
s3c_i2sv2_probe is enabling "iis" clock. And s3c2412_i2s_probe is enabling "i2sclk" and "mpll"clock. If, "mpll" clk_prepare_enable fails. We need to disable and free the clock "iis". and devm will handle other clock "i2sclk". In this code we have used "s3c2412_i2s.iis_cclk" for all the clock which is more confusing for me. Please correct me if i am wrong.
~arvind
On Wed, Jul 26, 2017 at 05:35:32PM +0530, Arvind Yadav wrote:
On Wednesday 26 July 2017 04:58 PM, Mark Brown wrote:
On Wed, Jul 26, 2017 at 11:15:25AM +0530, Arvind Yadav wrote:
+err:
- clk_disable(s3c2412_i2s.iis_pclk);
This will disable the clock if we failed to enable it which is clearly not correct. It's also matching a clk_prepare_enable() with a clk_disable() which is going to leave an unbalanced prepare.
s3c_i2sv2_probe is enabling "iis" clock. And s3c2412_i2s_probe is enabling "i2sclk" and "mpll"clock. If, "mpll" clk_prepare_enable fails. We need to disable and free the clock "iis". and devm will handle other clock "i2sclk". In this code we have used "s3c2412_i2s.iis_cclk" for all the clock which is more confusing for me. Please correct me if i am wrong.
OK, they are different clocks. This inconsistent handling seems like a big part of the problem though - it's going to be a source of errors. We're also still only disabling here, not unpreparing, so we're missing something.
On Wed, Jul 26, 2017 at 11:15:25AM +0530, Arvind Yadav wrote:
clk_prepare_enable() can fail here and we must check its return value.
Signed-off-by: Arvind Yadav arvind.yadav.cs@gmail.com
Chnage in v2 : Error handling for things done in s3c_i2sv2_probe().
sound/soc/samsung/s3c2412-i2s.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/sound/soc/samsung/s3c2412-i2s.c b/sound/soc/samsung/s3c2412-i2s.c index 0a47182..0b96927 100644 --- a/sound/soc/samsung/s3c2412-i2s.c +++ b/sound/soc/samsung/s3c2412-i2s.c @@ -65,13 +65,16 @@ static int s3c2412_i2s_probe(struct snd_soc_dai *dai) s3c2412_i2s.iis_cclk = devm_clk_get(dai->dev, "i2sclk"); if (IS_ERR(s3c2412_i2s.iis_cclk)) { pr_err("failed to get i2sclk clock\n");
return PTR_ERR(s3c2412_i2s.iis_cclk);
ret = PTR_ERR(s3c2412_i2s.iis_cclk);goto err;
No, this is kind of messy and error-prone. I think that each unit should rather clean by itself. You should not touch s3c_i2sv2 stuff directly.
Instead define a s3c_i2sv2_cleanup() (or remove() to match the convention?) and call it here on error-paths.
Best regards, Krzysztof
participants (3)
-
Arvind Yadav -
Krzysztof Kozlowski -
Mark Brown