Date: Thu, 24 May 2012 19:53:40 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: Alexander Motin <mav@freebsd.org> Cc: multimedia@freebsd.org Subject: Re: NV10 hdac issue Message-ID: <20120524165340.GN2358@deviant.kiev.zoral.com.ua> In-Reply-To: <4FBD8202.9010308@FreeBSD.org> References: <20120522220640.GB2358@deviant.kiev.zoral.com.ua> <4FBD2D50.5080205@FreeBSD.org> <20120523193718.GF2358@deviant.kiev.zoral.com.ua> <4FBD8202.9010308@FreeBSD.org>
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--wxwCHDD50Sxg6bJc Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 24, 2012 at 03:34:10AM +0300, Alexander Motin wrote: > On 05/23/12 22:37, Konstantin Belousov wrote: > >On Wed, May 23, 2012 at 09:32:48PM +0300, Alexander Motin wrote: > >>On 05/23/12 01:06, Konstantin Belousov wrote: > >>>I have (another) Atom motherboard from Intel, DN2800MT. Now, the probl= em > >>>is with distorted sound. Anything is played as if some pause is insert= ed > >>>after the next sample is finished. So I hear the proper pitch, but with > >>>guggle between fragments. I am not sure how to describe it better, exc= ept > >>>to say that it sounds as if buffering was not enough, for regular short > >>>intervals of approx. 0.5 sec. > >>> > >>>I do not believe that 1.8Hhz Atoms are too slow to decode mp3 or to pl= ay > >>>wav. > >>> > >>>The hda controller is > >>>hdac0@pci0:0:27:0: class=3D0x040300 card=3D0x20128086 chip=3D0x27= d88086 > >>>rev=3D0x02 hdr=3D0x00 > >>>codec is Realtek ALC888. The verbose dmesg from hda_snd load is at > >>>http://people.freebsd.org/~kib/tom.dmesg.txt , assuming this is useful. > >>> > >>>I would want to get normal sound from this board, thanks in advance. > >> > >>I haven't seen alike reports neither for this controller, nor for this > >>CODEC. I would try to experiment with: > >>1) disabling MSI interrupts with hint.hdac.0.msi=3D0 > >>2) switching to polling mode without using any interrupts with > >>dev.hdac.0.polling=3D1 > >>3) changing buffer size with hw.snd.latency > >>4) changing playback format (or vchans format it it is used) > >>5) setting sysctl hw.snd.verbose=3D2 and checking for application level > >>underruns with `cat /dev/sndstat`. > > > >Thank you, setting hw.snd.latency to 10 fixed the issue. Still, I do not > >understand why default settings for the driver are not enough for the > >machine. >=20 > latency=3D10 means buffering for about 0.3s, that is quite a lot. I've=20 > tested some systems with smallest possible buffer of just 0.6ms and they= =20 > were working about fine even in that case. The minimum value of hw.snd.latency where I do not hear the distortion is 9. >=20 > If it works for large buffer I would suppose that controller operates=20 > well, because using only two interrupts per period even single loss=20 > should be heard. Can't it be some insane SMI handler or something alike?= =20 > Aren't there any other lags noticed? I cannot say anything about SMI, but suppose that there is no other issues on this box. There is no noticeable lag under any other activity, like doing some maintanence work in shell, using the text editor (vi), as well as ping response times are reasonable and without much deviations. vmstat -i: interrupt total rate irq4: uart0 1111 0 irq19: uhci1 5343 2 irq20: hpet0 261172 108 irq23: ehci0 uhci0 2430 1 irq256: ahci0 1467 0 irq257: hdac0 6444 2 irq258: em0:rx 0 3133 1 irq259: em0:tx 0 652 0 irq260: em0:link 1 0 Total 281753 117 --wxwCHDD50Sxg6bJc Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (FreeBSD) iEYEARECAAYFAk++Z5QACgkQC3+MBN1Mb4gbnACfTotZ4pvWVlH8e7XjV7iSTxuD XzgAn1kSl/H23pAyMtP1XiPgMX+0MZfX =XwNa -----END PGP SIGNATURE----- --wxwCHDD50Sxg6bJc--
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