Re: [linux-audio-user] xinerama and alsa problems

Hmmm, this is interesting... I have a similar problem. Two videocards here, NVIDIA GeForce4 and a Matrox MGA400 (Dual Head) on a gentoo system. XFree 4.3.0 and Alsa 0.9.2. Kernel has low-latency enabled. If I enable the other videocard in XF86Config (simply by adding a screen section for it), when I get into X, ANY sound will have major clipping problems, and eventually my machine will TOTALLY LOCK, leaving the only way to save it to pull the frigging plug out the back. This is extremely frustrating. Even more frustrating is that things actually work just fine under WindowsXP, this is so wrong. (Although games do get a tiny bit of clipping once in a while). When the other video card is not used things work just perfectly! Have read many suggestions on net about this. Seems one possible solution is the soundcard needs to be on a low IRQ such as 9, however, no matter what I do (even moving card physically) its always sharing an IRQ with something. Right now the NVIDIA card and the Sound card are sharing the same IRQ, how braindead is this? Any clues would be much appreciated. Its been a long time since I had actually mess with the damn hardware. Does enabling APIC-IO in the kernel make any difference? Don't even know if my processer has APIC support. I mean this has got to work, if it can work fine under winblows, then I'm assuming there has got to be a way. Thanks -Ivan/ ------- root@durhamel iganza # cat /proc/pci PCI devices found: Bus 0, device 0, function 0: Host bridge: Intel Corp. 82850 850 (Tehama) Chipset Host Bridge (MCH) (rev 2). Prefetchable 32 bit memory at 0xd8000000 [0xdfffffff]. Bus 0, device 1, function 0: PCI bridge: Intel Corp. 82850 850 (Tehama) Chipset AGP Bridge (rev 2). Master Capable. Latency=64. Min Gnt=14. Bus 0, device 30, function 0: PCI bridge: Intel Corp. 82801BA/CA/DB PCI Bridge (rev 2). Master Capable. No bursts. Min Gnt=6. Bus 0, device 31, function 0: ISA bridge: Intel Corp. 82801BA ISA Bridge (LPC) (rev 2). Bus 0, device 31, function 1: IDE interface: Intel Corp. 82801BA IDE U100 (rev 2). I/O at 0xffa0 [0xffaf]. Bus 0, device 31, function 2: USB Controller: Intel Corp. 82801BA/BAM USB (Hub #1) (rev 2). IRQ 12. I/O at 0xff80 [0xff9f]. Bus 0, device 31, function 3: SMBus: Intel Corp. 82801BA/BAM SMBus (rev 2). IRQ 11. I/O at 0xdcd0 [0xdcdf]. Bus 0, device 31, function 4: USB Controller: Intel Corp. 82801BA/BAM USB (Hub #2) (rev 2). IRQ 10. I/O at 0xff60 [0xff7f]. Bus 1, device 0, function 0: VGA compatible controller: nVidia Corporation NV25 (GeForce 4) (rev 163). IRQ 9. Master Capable. Latency=248. Min Gnt=5.Max Lat=1. Non-prefetchable 32 bit memory at 0xfd000000 [0xfdffffff]. Prefetchable 32 bit memory at 0xe8000000 [0xefffffff]. Prefetchable 32 bit memory at 0xe7f80000 [0xe7ffffff]. Bus 2, device 10, function 0: PCI bridge: Hint Corp HB1-SE33 PCI-PCI Bridge (rev 18). Master Capable. Latency=64. Min Gnt=6. Bus 2, device 11, function 0: Multimedia audio controller: Creative Labs SB Audigy (rev 3). IRQ 9. Master Capable. Latency=64. Min Gnt=2.Max Lat=20. I/O at 0xece0 [0xecff]. Bus 2, device 11, function 1: Input device controller: Creative Labs SB Audigy MIDI/Game port (rev 3). Master Capable. Latency=64. I/O at 0xecd8 [0xecdf]. Bus 2, device 11, function 2: FireWire (IEEE 1394): Creative Labs SB Audigy FireWire Port (rev 0). IRQ 11. Master Capable. Latency=64. Min Gnt=2.Max Lat=4. Non-prefetchable 32 bit memory at 0xf9fff800 [0xf9ffffff]. Non-prefetchable 32 bit memory at 0xf9ff8000 [0xf9ffbfff]. Bus 2, device 12, function 0: Ethernet controller: 3Com Corporation 3c905C-TX/TX-M [Tornado] (rev 120). IRQ 5. Master Capable. Latency=64. Min Gnt=10.Max Lat=10. I/O at 0xec00 [0xec7f]. Non-prefetchable 32 bit memory at 0xf9fff400 [0xf9fff47f]. Bus 3, device 0, function 0: VGA compatible controller: Matrox Graphics, Inc. MGA G400 AGP (rev 133). IRQ 12. Master Capable. Latency=64. Min Gnt=16.Max Lat=32. Prefetchable 32 bit memory at 0xf0000000 [0xf1ffffff]. Non-prefetchable 32 bit memory at 0xfbffc000 [0xfbffffff]. Non-prefetchable 32 bit memory at 0xfb000000 [0xfb7fffff]. "Jack O'Quin" <joq(a)io.com> writes: >Arthur Moore <art(a)infinitybox.net> writes: > > > >>I'm using xinerama with two nvidia cards and I'm having a problem when >>trying to play sound. When I stretch an app (like audacity) over two >>screens I get all sorts of distortions. Actually whenever any sound >>app is on the second screen I have problems. Like a clicking. Anyway >>I'm using Debian unstable, with kernel 2.4.20 (no patches), Xfree86 >>4.2.1, and alsa 0.9.2. Anyone else seen this problem? >> >> >It works OK for me. I'm running Debian woody (stable), homemade >kernel 2.4.19 with lowlatency and capability patches, XFree86 4.1.0, >GNOME 1.4 and ALSA 0.9.0rc7-2 with xinerama on a Matrox G400. Sound >card is an M-Audio Delta 66 (very good card for the money). > >The first thing I'd suspect is the NVIDIA cards. Some models are >reputed to have poor latency characteristics. Google for information >on what the problems are and what to do. > >You may want to try building a low-latency kernel, too. Debian has a >package for it that you can install and include in the kernel build >with make-kpkg. If you're going to do all that, I'd recommend making >the capability patch, also. It's only two lines, and it makes JACK >far more usable. > >Regards, >-- > Jack O'Quin > >