[PATCH RESEND] ASoC: mediatek: mt8195: optimize property formatting error handling by using scnprintf()

[PATCH RESEND] ASoC: mediatek: mt8195: optimize property formatting error handling by using scnprintf()

[hariconscious]

From: HariKrishna Sagala <hariconscious@gmail.com>

Replace snprintf() with scnprintf() when constructing the property
and remove negative return error handling as scnprintf() returns the
actual number of bytes written to buffer.

snprintf() as defined by the C99 standard,returns the number of 
characters that *would have been* written if enough space were 
available.Use scnprintf() that returns the actual number of 
characters written.

Link: https://github.com/KSPP/linux/issues/105
Signed-off-by: HariKrishna Sagala <hariconscious@gmail.com>
---
This patch optimizes the error handling part of property formatting
using the scnrpintf().
Removed the error check ret < 0 as scnprintf() doesn't return the
negative value as per contract.
https://www.kernel.org/doc/html/latest/core-api/kernel-api.html#c.scnprintf

Thank you.

 sound/soc/mediatek/mt8195/mt8195-dai-etdm.c | 44 ++++++---------------
 1 file changed, 12 insertions(+), 32 deletions(-)

diff --git a/sound/soc/mediatek/mt8195/mt8195-dai-etdm.c b/sound/soc/mediatek/mt8195/mt8195-dai-etdm.c
index fd4f9f8f032d..77c58c9ec3e2 100644
--- a/sound/soc/mediatek/mt8195/mt8195-dai-etdm.c
+++ b/sound/soc/mediatek/mt8195/mt8195-dai-etdm.c
@@ -2652,14 +2652,9 @@ static void mt8195_dai_etdm_parse_of(struct mtk_base_afe *afe)
 
 		etdm_data = afe_priv->dai_priv[dai_id];
 
-		ret = snprintf(prop, sizeof(prop),
-			       "mediatek,%s-mclk-always-on-rate",
-			       of_afe_etdms[i].name);
-		if (ret < 0) {
-			dev_info(afe->dev, "%s snprintf err=%d\n",
-				 __func__, ret);
-			return;
-		}
+		scnprintf(prop, sizeof(prop),
+			    "mediatek,%s-mclk-always-on-rate",
+			    of_afe_etdms[i].name);
 		ret = of_property_read_u32(of_node, prop, &sel);
 		if (ret == 0) {
 			etdm_data->mclk_dir = SND_SOC_CLOCK_OUT;
@@ -2668,24 +2663,14 @@ static void mt8195_dai_etdm_parse_of(struct mtk_base_afe *afe)
 					 __func__, sel);
 		}
 
-		ret = snprintf(prop, sizeof(prop),
-			       "mediatek,%s-multi-pin-mode",
-			       of_afe_etdms[i].name);
-		if (ret < 0) {
-			dev_info(afe->dev, "%s snprintf err=%d\n",
-				 __func__, ret);
-			return;
-		}
+		scnprintf(prop, sizeof(prop),
+			    "mediatek,%s-multi-pin-mode",
+			    of_afe_etdms[i].name);
 		etdm_data->data_mode = of_property_read_bool(of_node, prop);
 
-		ret = snprintf(prop, sizeof(prop),
-			       "mediatek,%s-cowork-source",
-			       of_afe_etdms[i].name);
-		if (ret < 0) {
-			dev_info(afe->dev, "%s snprintf err=%d\n",
-				 __func__, ret);
-			return;
-		}
+		scnprintf(prop, sizeof(prop),
+			    "mediatek,%s-cowork-source",
+			    of_afe_etdms[i].name);
 		ret = of_property_read_u32(of_node, prop, &sel);
 		if (ret == 0) {
 			if (sel >= MT8195_AFE_IO_ETDM_NUM) {
@@ -2707,14 +2692,9 @@ static void mt8195_dai_etdm_parse_of(struct mtk_base_afe *afe)
 		dai_id = ETDM_TO_DAI_ID(i);
 		etdm_data = afe_priv->dai_priv[dai_id];
 
-		ret = snprintf(prop, sizeof(prop),
-			       "mediatek,%s-chn-disabled",
-			       of_afe_etdms[i].name);
-		if (ret < 0) {
-			dev_info(afe->dev, "%s snprintf err=%d\n",
-				 __func__, ret);
-			return;
-		}
+		scnprintf(prop, sizeof(prop),
+			    "mediatek,%s-chn-disabled",
+			    of_afe_etdms[i].name);
 		ret = of_property_read_variable_u8_array(of_node, prop,
 							 disable_chn,
 							 1, max_chn);

base-commit: 30f09200cc4aefbd8385b01e41bde2e4565a6f0e
-- 
2.43.0

Re: [PATCH RESEND] ASoC: mediatek: mt8195: optimize property formatting error handling by using scnprintf()

[Mark Brown]

On Fri, 12 Dec 2025 10:14:09 +0530, hariconscious@gmail.com wrote:
> Replace snprintf() with scnprintf() when constructing the property
> and remove negative return error handling as scnprintf() returns the
> actual number of bytes written to buffer.
> 
> snprintf() as defined by the C99 standard,returns the number of
> characters that *would have been* written if enough space were
> available.Use scnprintf() that returns the actual number of
> characters written.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: mediatek: mt8195: optimize property formatting error handling by using scnprintf()
      commit: 180cdb96e821e30528b02708b927c93daa0ed40b

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark