From: Takashi Iwai <tiwai@suse.de>
To: "Hans Hu(SH-RD)" <HansHu@zhaoxin.com>
Cc: "'alsa-devel@alsa-project.org'" <alsa-devel@alsa-project.org>
Subject: Re: A bug about cache inconsistency report
Date: Tue, 31 Jul 2018 13:59:20 +0200 [thread overview]
Message-ID: <s5h600vr4yv.wl-tiwai@suse.de> (raw)
In-Reply-To: <c859756ba7f742869642fd80a105c3c8@zhaoxin.com>
On Tue, 31 Jul 2018 12:52:04 +0200,
Hans Hu(SH-RD) wrote:
>
> Hi All,
>
> Try send an email.
>
> Appearance:
> when use non-snoop + ioctl path combination, an issue occurs:
> usage: aplay -D plughw:0,0 44100_S16_LE_2c.wav
> Ubuntu, it performance intermittently noise;
>
> Root case:
> Function set_pages_array_wc marked the PTE of the original address; Function set_memory_wc marked the PTE both original and after vmaped address.
> [cid:image002.png@01D428FF.92621520]
> However, cache or not in transmission process is based on the PTE of the later, and the set_pages_array_wc did't mark it, so a cache inconsistency issue occurs.
>
> Related bug:
> SHA1 ID: 9ddf1aeb2134e72275c97a2c6ff2e3eb04f2f27a
OK, so did you confirm that dropping the SG buffer support "fixes" the
noise problem on your system? The easiest test would be like:
--- a/sound/pci/hda/hda_controller.c
+++ b/sound/pci/hda/hda_controller.c
@@ -770,7 +770,7 @@ int snd_hda_attach_pcm_stream(struct hda_bus *_bus, struct hda_codec *codec,
size = CONFIG_SND_HDA_PREALLOC_SIZE * 1024;
if (size > MAX_PREALLOC_SIZE)
size = MAX_PREALLOC_SIZE;
- snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV_SG,
+ snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
chip->card->dev,
size, MAX_PREALLOC_SIZE);
return 0;
thanks,
Takashi
next prev parent reply other threads:[~2018-07-31 11:59 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-31 10:52 A bug about cache inconsistency report Hans Hu(SH-RD)
2018-07-31 11:59 ` Takashi Iwai [this message]
[not found] ` <05a9e8e374994ada9d195b7cc6a08d07@zhaoxin.com>
2018-07-31 13:55 ` 答复: " Takashi Iwai
2018-08-01 2:05 Hans Hu(SH-RD)
2018-08-01 4:45 ` Takashi Iwai
2018-08-02 8:22 Hans Hu(SH-RD)
2018-08-02 8:50 ` Takashi Iwai
2018-08-07 9:00 Hans Hu(SH-RD)
2018-08-07 9:25 ` Takashi Iwai
2018-08-08 11:07 Hans Hu(SH-RD)
2018-08-10 15:15 ` Takashi Iwai
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