Subject: [linux-audio-user] full duplex latency on ac97 / kernel woes
From: Swirl Ly (swirlee_AT_hotmail.com)
Date: Mon Jan 21 2002 - 22:10:58 EET
ughhh. kernel & realtime audio config...
running realtime effects tests--
jackd 0.4.7 hangs computer periodically at buffersize 64 and 128.. but 256
seems to work okay, running passthrough test jack_simple_client on the
onboard ac97.
ecasound same thing, i get underruns.
latencytest, got latencies consistently around 1.16 ms,so buffersize 128
should definitely work. funny thing, i had to kill magicdev, the gnome probe
for inserting floppies and cds, because it was producing 160 ms spikes in my
latency during disk read/write/copy tests. isnt that funny? so im in the
process of recompiling kernel without floppy, cd, to see if no DMA on the cd
and floppy are the culprit?
i posted earlier, no response? could this be a hardware issue with the
ac97? because my kernel latencies seem to be OK, yet im still getting
underruns in ecasound and jackd.
once again, proc/sys:
::::::::::::::
/proc/pci
::::::::::::::
PCI devices found:
Bus 0, device 0, function 0:
Host bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133] (rev 3).
Master Capable. Latency=8.
Prefetchable 32 bit memory at 0xd0000000 [0xd3ffffff].
Bus 0, device 1, function 0:
PCI bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133 AGP] (rev
0).
Master Capable. No bursts. Min Gnt=4.
Bus 0, device 7, function 0:
ISA bridge: VIA Technologies, Inc. VT82C686 [Apollo Super South] (rev
64).
Bus 0, device 7, function 1:
IDE interface: VIA Technologies, Inc. Bus Master IDE (rev 6).
Master Capable. Latency=32.
I/O at 0xc000 [0xc00f].
Bus 0, device 7, function 4:
Host bridge: VIA Technologies, Inc. VT82C686 [Apollo Super ACPI] (rev
64).
IRQ 9.
Bus 0, device 7, function 5:
Multimedia audio controller: VIA Technologies, Inc. AC97 Audio
Controller (rev 80).
IRQ 10.
I/O at 0xcc00 [0xccff].
I/O at 0xd000 [0xd003].
I/O at 0xd400 [0xd403].
Bus 0, device 9, function 0:
VGA compatible controller: ATI Technologies Inc 3D Rage Pro 215GP (rev
92).
IRQ 11.
Master Capable. Latency=32. Min Gnt=8.
Prefetchable 32 bit memory at 0xd4000000 [0xd4ffffff].
I/O at 0xdc00 [0xdcff].
Non-prefetchable 32 bit memory at 0xd6101000 [0xd6101fff].
Bus 0, device 13, function 0:
Ethernet controller: Intel Corp. 82557 [Ethernet Pro 100] (rev 4).
IRQ 11.
Master Capable. Latency=32. Min Gnt=8.Max Lat=56.
Prefetchable 32 bit memory at 0xd6100000 [0xd6100fff].
I/O at 0xe000 [0xe01f].
Non-prefetchable 32 bit memory at 0xd6000000 [0xd60fffff].
running xfree 4.0.6? culprit??? kernel 2.4.18-pre4 patched with morton's
lowlatency.
thanks,
yon
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