[PATCH 1/2] ASoC: codecs: ad193x: Fix memory corruption on BE 64b systems

[PATCH 1/2] ASoC: codecs: ad193x: Fix memory corruption on BE 64b systems

[Codrin Ciubotariu]

Since change_bit() requires unsigned long*, making this cast on an
unsigned int variable will change a wrong bit on BE platforms, causing
memory corruption. Replace this function with a simple XOR.

Fixes: 90f6e6803139 ("ASoC: codecs: ad193x: Fix frame polarity for DSP_A format")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
---
 sound/soc/codecs/ad193x.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/sound/soc/codecs/ad193x.c b/sound/soc/codecs/ad193x.c
index 05f4514048e2..3ebc0524f4b2 100644
--- a/sound/soc/codecs/ad193x.c
+++ b/sound/soc/codecs/ad193x.c
@@ -240,10 +240,8 @@ static int ad193x_set_dai_fmt(struct snd_soc_dai *codec_dai,
 	}
 
 	/* For DSP_*, LRCLK's polarity must be inverted */
-	if (fmt & SND_SOC_DAIFMT_DSP_A) {
-		change_bit(ffs(AD193X_DAC_LEFT_HIGH) - 1,
-			   (unsigned long *)&dac_fmt);
-	}
+	if (fmt & SND_SOC_DAIFMT_DSP_A)
+		dac_fmt ^= AD193X_DAC_LEFT_HIGH;
 
 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
 	case SND_SOC_DAIFMT_CBM_CFM: /* codec clk & frm master */
-- 
2.20.1

[PATCH 2/2] ASoC: codecs: ad193x: Reset DAC Control 1 register at probe

[Codrin Ciubotariu]

Since the ad193x codecs have no software reset, we have to reinitialize the
registers after a hardware reset. For example, if we change the
device-tree between these resets, changing the audio format of the DAI link
from DSP_A with 8 TDM channels to I2S 2 channels, DAC Control 1 register
will remain configured for 8 channels. This patch resets this register at
probe to its default value.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
---
 sound/soc/codecs/ad193x.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/soc/codecs/ad193x.c b/sound/soc/codecs/ad193x.c
index 3ebc0524f4b2..cda435562a1d 100644
--- a/sound/soc/codecs/ad193x.c
+++ b/sound/soc/codecs/ad193x.c
@@ -427,6 +427,8 @@ static int ad193x_component_probe(struct snd_soc_component *component)
 	regmap_write(ad193x->regmap, AD193X_DAC_CTRL2, 0x1A);
 	/* dac in tdm mode */
 	regmap_write(ad193x->regmap, AD193X_DAC_CTRL0, 0x40);
+	/* reset DAC ctrl1 */
+	regmap_write(ad193x->regmap, AD193X_DAC_CTRL1, 0x00);
 
 	/* adc only */
 	if (ad193x_has_adc(ad193x)) {
-- 
2.20.1

Re: [PATCH 2/2] ASoC: codecs: ad193x: Reset DAC Control 1 register at probe

[Mark Brown]

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On Wed, Jun 26, 2019 at 01:49:47PM +0300, Codrin Ciubotariu wrote:
> Since the ad193x codecs have no software reset, we have to reinitialize the
> registers after a hardware reset. For example, if we change the
> device-tree between these resets, changing the audio format of the DAI link
> from DSP_A with 8 TDM channels to I2S 2 channels, DAC Control 1 register
> will remain configured for 8 channels. This patch resets this register at
> probe to its default value.

Would it not be more robust/complete to have a set of register defaults
and write the whole lot out rather than individually going through and
adding writes for specific registers as needed?

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Applied "ASoC: codecs: ad193x: Fix memory corruption on BE 64b systems" to the asoc tree

[Mark Brown]

The patch

   ASoC: codecs: ad193x: Fix memory corruption on BE 64b systems

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.2

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

From da7260cc8d1dc3564eb4f33550b0525541d71a47 Mon Sep 17 00:00:00 2001
From: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Date: Wed, 26 Jun 2019 13:49:46 +0300
Subject: [PATCH] ASoC: codecs: ad193x: Fix memory corruption on BE 64b systems

Since change_bit() requires unsigned long*, making this cast on an
unsigned int variable will change a wrong bit on BE platforms, causing
memory corruption. Replace this function with a simple XOR.

Fixes: 90f6e6803139 ("ASoC: codecs: ad193x: Fix frame polarity for DSP_A format")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/codecs/ad193x.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/sound/soc/codecs/ad193x.c b/sound/soc/codecs/ad193x.c
index 96d7cb2e4a56..16e2d334bbe0 100644
--- a/sound/soc/codecs/ad193x.c
+++ b/sound/soc/codecs/ad193x.c
@@ -241,10 +241,8 @@ static int ad193x_set_dai_fmt(struct snd_soc_dai *codec_dai,
 	}
 
 	/* For DSP_*, LRCLK's polarity must be inverted */
-	if (fmt & SND_SOC_DAIFMT_DSP_A) {
-		change_bit(ffs(AD193X_DAC_LEFT_HIGH) - 1,
-			   (unsigned long *)&dac_fmt);
-	}
+	if (fmt & SND_SOC_DAIFMT_DSP_A)
+		dac_fmt ^= AD193X_DAC_LEFT_HIGH;
 
 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
 	case SND_SOC_DAIFMT_CBM_CFM: /* codec clk & frm master */
-- 
2.20.1

Re: [PATCH 2/2] ASoC: codecs: ad193x: Reset DAC Control 1 register at probe

[Codrin.Ciubotariu]

On 26.06.2019 14:23, Mark Brown wrote:
> On Wed, Jun 26, 2019 at 01:49:47PM +0300, Codrin Ciubotariu wrote:
>> Since the ad193x codecs have no software reset, we have to reinitialize the
>> registers after a hardware reset. For example, if we change the
>> device-tree between these resets, changing the audio format of the DAI link
>> from DSP_A with 8 TDM channels to I2S 2 channels, DAC Control 1 register
>> will remain configured for 8 channels. This patch resets this register at
>> probe to its default value.
> 
> Would it not be more robust/complete to have a set of register defaults
> and write the whole lot out rather than individually going through and
> adding writes for specific registers as needed?
> 

It would indeed. I will make two patches, one that implements what you 
suggested, for the registers that we touch only, and another one that 
will add AD193X_DAC_CTRL1 to these defaults. You can drop this patch.

Thanks and best regards,
Codrin