All of lore.kernel.org
 help / color / mirror / Atom feed
From: Akshu Agrawal <akshu.agrawal@amd.com>
To: unlisted-recipients:; (no To-header on input)
Cc: akshu.agrawal@amd.com, djkurtz@chromium.org,
	Alexander.Deucher@amd.com, Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>, Jaroslav Kysela <perex@perex.cz>,
	Takashi Iwai <tiwai@suse.com>,
	"Mukunda, Vijendar" <Vijendar.Mukunda@amd.com>,
	Alex Deucher <alexander.deucher@amd.com>,
	alsa-devel@alsa-project.org (moderated list:SOUND - SOC LAYER /
	DYNAMIC AUDIO POWER MANAGEM...),
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] ASoC: AMD: Fix capture unstable in beginning for some runs
Date: Mon, 17 Sep 2018 21:10:34 +0530	[thread overview]
Message-ID: <1537198839-15985-1-git-send-email-akshu.agrawal@amd.com> (raw)

alsa_conformance_test -C hw:0,4 -p 1024 --debug
would sometime show:
TIME_DIFF(s)    HW_LEVEL       READ              RATE
0.000095970         1024       1024    10670001.041992
0.042609555         1024       2048       24032.168372
0.021330364         1024       3072       48006.681930
0.021339559         1024       4096       47985.996337
The issue is that in dma pointer function we can have stale value
of the register for current descriptor of channel.
The register retains the number of the last descriptor that
was transferred.

Fix ensures that we report position, 0, till the one period worth of
data is transferred.  After one period of data, in handler of period
completion interrupt we update the config and correct value of descriptor
starts reflecting.

Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
---
 sound/soc/amd/acp-pcm-dma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c
index c7e972b..f27e20c 100644
--- a/sound/soc/amd/acp-pcm-dma.c
+++ b/sound/soc/amd/acp-pcm-dma.c
@@ -1050,6 +1050,8 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream)
 			bytescount -= rtd->bytescount;
 		delay = do_div(bytescount, period_bytes);
 		runtime->delay = bytes_to_frames(runtime, delay);
+		if (bytescount < period_bytes)
+			pos = 0;
 	} else {
 		buffersize = frames_to_bytes(runtime, runtime->buffer_size);
 		bytescount = acp_get_byte_count(rtd);
-- 
1.9.1


WARNING: multiple messages have this Message-ID (diff)
From: Akshu Agrawal <akshu.agrawal@amd.com>
Cc: akshu.agrawal@amd.com, djkurtz@chromium.org,
	Alexander.Deucher@amd.com, Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>, Jaroslav Kysela <perex@perex.cz>,
	Takashi Iwai <tiwai@suse.com>,
	"Mukunda, Vijendar" <Vijendar.Mukunda@amd.com>,
	Alex Deucher <alexander.deucher@amd.com>,
	"moderated list:SOUND - SOC LAYER / DYNAMIC AUDIO POWER
	MANAGEM..." <alsa-devel@alsa-project.org>,
	open list <linux-kernel@vger.kernel.org>
Subject: [PATCH] ASoC: AMD: Fix capture unstable in beginning for some runs
Date: Mon, 17 Sep 2018 21:10:34 +0530	[thread overview]
Message-ID: <1537198839-15985-1-git-send-email-akshu.agrawal@amd.com> (raw)

alsa_conformance_test -C hw:0,4 -p 1024 --debug
would sometime show:
TIME_DIFF(s)    HW_LEVEL       READ              RATE
0.000095970         1024       1024    10670001.041992
0.042609555         1024       2048       24032.168372
0.021330364         1024       3072       48006.681930
0.021339559         1024       4096       47985.996337
The issue is that in dma pointer function we can have stale value
of the register for current descriptor of channel.
The register retains the number of the last descriptor that
was transferred.

Fix ensures that we report position, 0, till the one period worth of
data is transferred.  After one period of data, in handler of period
completion interrupt we update the config and correct value of descriptor
starts reflecting.

Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
---
 sound/soc/amd/acp-pcm-dma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c
index c7e972b..f27e20c 100644
--- a/sound/soc/amd/acp-pcm-dma.c
+++ b/sound/soc/amd/acp-pcm-dma.c
@@ -1050,6 +1050,8 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream)
 			bytescount -= rtd->bytescount;
 		delay = do_div(bytescount, period_bytes);
 		runtime->delay = bytes_to_frames(runtime, delay);
+		if (bytescount < period_bytes)
+			pos = 0;
 	} else {
 		buffersize = frames_to_bytes(runtime, runtime->buffer_size);
 		bytescount = acp_get_byte_count(rtd);
-- 
1.9.1

             reply	other threads:[~2018-09-17 15:46 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-17 15:40 Akshu Agrawal [this message]
2018-09-17 15:40 ` [PATCH] ASoC: AMD: Fix capture unstable in beginning for some runs Akshu Agrawal

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1537198839-15985-1-git-send-email-akshu.agrawal@amd.com \
    --to=akshu.agrawal@amd.com \
    --cc=Alexander.Deucher@amd.com \
    --cc=Vijendar.Mukunda@amd.com \
    --cc=alsa-devel@alsa-project.org \
    --cc=broonie@kernel.org \
    --cc=djkurtz@chromium.org \
    --cc=lgirdwood@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=perex@perex.cz \
    --cc=tiwai@suse.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.