[PATCHv1] ASoC: cpcap: fix microphone timeslot mask

[PATCHv1] ASoC: cpcap: fix microphone timeslot mask

[Sebastian Reichel]

The correct mask is 0x1f8 (Bit 3-8), but due to missing BIT() 0xf (Bit
0-3) was set instead. This means setting of CPCAP_BIT_MIC1_RX_TIMESLOT0
(Bit 3) still worked (part of both masks). On the other hand the code
does not properly clear the other MIC timeslot bits. I think this
is not a problem, since they are probably initialized to 0 and not
touched by the driver anywhere else. But the mask also contains some
wrong bits, that will be cleared. Bit 0 (CPCAP_BIT_SMB_CDC) should be
safe, since the driver enforces it to be 0 anyways.

Bit 1-2 are CPCAP_BIT_FS_INV and CPCAP_BIT_CLK_INV. This means enabling
audio recording forces the codec into SND_SOC_DAIFMT_NB_NF mode, which
is obviously bad.

The bug probably remained undetected, because there are not many use
cases for routing microphone to the CPU on platforms using cpcap and
user base is small. I do remember having some issues with bad sound
quality when testing voice recording back when I wrote the driver.
It probably was this bug.

Fixes: f6cdf2d3445d ("ASoC: cpcap: new codec")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
---
Hi,

This is compile tested only, since I currently do not have
my Droid 4 ready for running some tests. Maybe Tony, Pavel or
Merlijn can give it a go using e.g. arecord.

Thanks,

-- Sebastian
---
 sound/soc/codecs/cpcap.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/sound/soc/codecs/cpcap.c b/sound/soc/codecs/cpcap.c
index e266d993ab2a..05bbacd0d174 100644
--- a/sound/soc/codecs/cpcap.c
+++ b/sound/soc/codecs/cpcap.c
@@ -1273,12 +1273,12 @@ static int cpcap_voice_hw_params(struct snd_pcm_substream *substream,
 
 	if (direction == SNDRV_PCM_STREAM_CAPTURE) {
 		mask = 0x0000;
-		mask |= CPCAP_BIT_MIC1_RX_TIMESLOT0;
-		mask |= CPCAP_BIT_MIC1_RX_TIMESLOT1;
-		mask |= CPCAP_BIT_MIC1_RX_TIMESLOT2;
-		mask |= CPCAP_BIT_MIC2_TIMESLOT0;
-		mask |= CPCAP_BIT_MIC2_TIMESLOT1;
-		mask |= CPCAP_BIT_MIC2_TIMESLOT2;
+		mask |= BIT(CPCAP_BIT_MIC1_RX_TIMESLOT0);
+		mask |= BIT(CPCAP_BIT_MIC1_RX_TIMESLOT1);
+		mask |= BIT(CPCAP_BIT_MIC1_RX_TIMESLOT2);
+		mask |= BIT(CPCAP_BIT_MIC2_TIMESLOT0);
+		mask |= BIT(CPCAP_BIT_MIC2_TIMESLOT1);
+		mask |= BIT(CPCAP_BIT_MIC2_TIMESLOT2);
 		val = 0x0000;
 		if (channels >= 2)
 			val = BIT(CPCAP_BIT_MIC1_RX_TIMESLOT0);
-- 
2.29.2

Re: [PATCHv1] ASoC: cpcap: fix microphone timeslot mask

[Tony Lindgren]

* Sebastian Reichel <sre@kernel.org> [210123 17:30]:
> This is compile tested only, since I currently do not have
> my Droid 4 ready for running some tests. Maybe Tony, Pavel or
> Merlijn can give it a go using e.g. arecord.

I just tried recording with arecord -D plughw:CARD=Audio,DEV=1 | hd
but only see the header and no data.. DEV=0 won't produce anything,
maybe I have the alsamixer settings wrong. Let me know if you want
me to try something else.

I do have the pending voice call patches applied on top, voice calls
work just fine with your patch. So as it looks correct to me:

Reviewed-by: Tony Lindgren <tony@atomide.com>

Re: [PATCHv1] ASoC: cpcap: fix microphone timeslot mask

[Mark Brown]

On Sat, 23 Jan 2021 18:29:45 +0100, Sebastian Reichel wrote:
> The correct mask is 0x1f8 (Bit 3-8), but due to missing BIT() 0xf (Bit
> 0-3) was set instead. This means setting of CPCAP_BIT_MIC1_RX_TIMESLOT0
> (Bit 3) still worked (part of both masks). On the other hand the code
> does not properly clear the other MIC timeslot bits. I think this
> is not a problem, since they are probably initialized to 0 and not
> touched by the driver anywhere else. But the mask also contains some
> wrong bits, that will be cleared. Bit 0 (CPCAP_BIT_SMB_CDC) should be
> safe, since the driver enforces it to be 0 anyways.
> 
> [...]

Applied to

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

Thanks!

[1/1] ASoC: cpcap: fix microphone timeslot mask
      commit: de5bfae2fd962a9da99f56382305ec7966a604b9

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