From: Jens Axboe <axboe@kernel.dk>
To: perex@perex.cz, tiwai@suse.com, kai.vehmanen@linux.intel.com,
alsa-devel@alsa-project.org
Subject: azx_get_pos_skl() induced system slowness
Date: Tue, 24 Aug 2021 11:38:08 -0600 [thread overview]
Message-ID: <402d5952-3bf6-5c0d-5276-8367bfe1542a@kernel.dk> (raw)
Hi,
Got a new notebook recently, it's a Lenovo X1 Carbon 9th gen. Sound
works fine, but sometimes I get really stuttering playback from nestopia
and I finally decided to look into it. When this happens,
azx_get_pos_skl() is seemingly called a lot, at least it uses a ton of
CPU cycles. This comes and goes, sometimes 1 minute in between,
sometimes 2, and sometimes 30 seconds.
If I comment out the udelay() in that function it does seems to be
noticeably better, though it's not a complete fix. I guess it just
reduces the pain of calling it so many times?
This is running 5.14-rc7, but it's not a recent regression.
Any clues as to what this might be?
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 470753b36c8a..3c1f233e463f 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -878,7 +878,9 @@ static unsigned int azx_get_pos_skl(struct azx *chip, struct azx_dev *azx_dev)
* for the possible boundary overlap; the read of DPIB fetches the
* actual posbuf
*/
+#if 0
udelay(20);
+#endif
azx_skl_get_dpib_pos(chip, azx_dev);
return azx_get_pos_posbuf(chip, azx_dev);
}
--
Jens Axboe
next reply other threads:[~2021-08-25 6:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-24 17:38 Jens Axboe [this message]
2021-08-25 6:14 ` azx_get_pos_skl() induced system slowness Takashi Iwai
2021-08-25 12:33 ` Jens Axboe
2021-08-26 6:08 ` Takashi Iwai
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=402d5952-3bf6-5c0d-5276-8367bfe1542a@kernel.dk \
--to=axboe@kernel.dk \
--cc=alsa-devel@alsa-project.org \
--cc=kai.vehmanen@linux.intel.com \
--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.