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diff --git a/Documentation/sound/oss/NM256 b/Documentation/sound/oss/NM256 new file mode 100644 index 000000000000..b503217488b3 --- /dev/null +++ b/Documentation/sound/oss/NM256 @@ -0,0 +1,280 @@ +======================================================= +Documentation for the NeoMagic 256AV/256ZX sound driver +======================================================= + +You're looking at version 1.1 of the driver. (Woohoo!) It has been +successfully tested against the following laptop models: + + Sony Z505S/Z505SX/Z505DX/Z505RX + Sony F150, F160, F180, F250, F270, F280, PCG-F26 + Dell Latitude CPi, CPt (various submodels) + +There are a few caveats, which is why you should read the entirety of +this document first. + +This driver was developed without any support or assistance from +NeoMagic. There is no warranty, expressed, implied, or otherwise. It +is free software in the public domain; feel free to use it, sell it, +give it to your best friends, even claim that you wrote it (but why?!) +but don't go whining to me, NeoMagic, Sony, Dell, or anyone else +when it blows up your computer. + +Version 1.1 contains a change to try and detect non-AC97 versions of +the hardware, and not install itself appropriately. It should also +reinitialize the hardware on an APM resume event, assuming that APM +was configured into your kernel. + +============ +Installation +============ + +Enable the sound drivers, the OSS sound drivers, and then the NM256 +driver. The NM256 driver *must* be configured as a module (it won't +give you any other choice). + +Next, do the usual "make modules" and "make modules_install". +Finally, insmod the soundcore, sound and nm256 modules. + +When the nm256 driver module is loaded, you should see a couple of +confirmation messages in the kernel logfile indicating that it found +the device (the device does *not* use any I/O ports or DMA channels). +Now try playing a wav file, futz with the CD-ROM if you have one, etc. + +The NM256 is entirely a PCI-based device, and all the necessary +information is automatically obtained from the card. It can only be +configured as a module in a vain attempt to prevent people from +hurting themselves. It works correctly if it shares an IRQ with +another device (it normally shares IRQ 9 with the builtin eepro100 +ethernet on the Sony Z505 laptops). + +It does not run the card in any sort of compatibility mode. It will +not work on laptops that have the SB16-compatible, AD1848-compatible +or CS4232-compatible codec/mixer; you will want to use the appropriate +compatible OSS driver with these chipsets. I cannot provide any +assistance with machines using the SB16, AD1848 or CS4232 compatible +versions. (The driver now attempts to detect the mixer version, and +will refuse to load if it believes the hardware is not +AC97-compatible.) + +The sound support is very basic, but it does include simultaneous +playback and record capability. The mixer support is also quite +simple, although this is in keeping with the rather limited +functionality of the chipset. + +There is no hardware synthesizer available, as the Losedows OPL-3 and +MIDI support is done via hardware emulation. + +Only three recording devices are available on the Sony: the +microphone, the CD-ROM input, and the volume device (which corresponds +to the stereo output). (Other devices may be available on other +models of laptops.) The Z505 series does not have a builtin CD-ROM, +so of course the CD-ROM input doesn't work. It does work on laptops +with a builtin CD-ROM drive. + +The mixer device does not appear to have any tone controls, at least +on the Z505 series. The mixer module checks for tone controls in the +AC97 mixer, and will enable them if they are available. + +============== +Known problems +============== + + * There are known problems with PCMCIA cards and the eepro100 ethernet + driver on the Z505S/Z505SX/Z505DX. Keep reading. + + * There are also potential problems with using a virtual X display, and + also problems loading the module after the X server has been started. + Keep reading. + + * The volume control isn't anywhere near linear. Sorry. This will be + fixed eventually, when I get sufficiently annoyed with it. (I doubt + it will ever be fixed now, since I've never gotten sufficiently + annoyed with it and nobody else seems to care.) + + * There are reports that the CD-ROM volume is very low. Since I do not + have a CD-ROM equipped laptop, I cannot test this (it's kinda hard to + do remotely). + + * Only 8 fixed-rate speeds are supported. This is mainly a chipset + limitation. It may be possible to support other speeds in the future. + + * There is no support for the telephone mixer/codec. There is support + for a phonein/phoneout device in the mixer driver; whether or not + it does anything is anyone's guess. (Reports on this would be + appreciated. You'll have to figure out how to get the phone to + go off-hook before it'll work, tho.) + + * This driver was not written with any cooperation or support from + NeoMagic. If you have any questions about this, see their website + for their official stance on supporting open source drivers. + +============ +Video memory +============ + +The NeoMagic sound engine uses a portion of the display memory to hold +the sound buffer. (Crazy, eh?) The NeoMagic video BIOS sets up a +special pointer at the top of video RAM to indicate where the top of +the audio buffer should be placed. + +At the present time XFree86 is apparently not aware of this. It will +thus write over either the pointer or the sound buffer with abandon. +(Accelerated-X seems to do a better job here.) + +This implies a few things: + + * Sometimes the NM256 driver has to guess at where the buffer + should be placed, especially if the module is loaded after the + X server is started. It's usually correct, but it will consistently + fail on the Sony F250. + + * Virtual screens greater than 1024x768x16 under XFree86 are + problematic on laptops with only 2.5MB of screen RAM. This + includes all of the 256AV-equipped laptops. (Virtual displays + may or may not work on the 256ZX, which has at least 4MB of + video RAM.) + +If you start having problems with random noise being output either +constantly (this is the usual symptom on the F250), or when windows +are moved around (this is the usual symptom when using a virtual +screen), the best fix is to + + * Don't use a virtual frame buffer. + * Make sure you load the NM256 module before the X server is + started. + +On the F250, it is possible to force the driver to load properly even +after the XFree86 server is started by doing: + + insmod nm256 buffertop=0x25a800 + +This forces the audio buffers to the correct offset in screen RAM. + +One user has reported a similar problem on the Sony F270, although +others apparently aren't seeing any problems. His suggested command +is + + insmod nm256 buffertop=0x272800 + +================= +Official WWW site +================= + +The official site for the NM256 driver is: + + http://www.uglx.org/sony.html + +You should always be able to get the latest version of the driver there, +and the driver will be supported for the foreseeable future. + +============== +Z505RX and IDE +============== + +There appears to be a problem with the IDE chipset on the Z505RX; one +of the symptoms is that sound playback periodically hangs (when the +disk is accessed). The user reporting the problem also reported that +enabling all of the IDE chipset workarounds in the kernel solved the +problem, tho obviously only one of them should be needed--if someone +can give me more details I would appreciate it. + +============================== +Z505S/Z505SX on-board Ethernet +============================== + +If you're using the on-board Ethernet Pro/100 ethernet support on the Z505 +series, I strongly encourage you to download the latest eepro100 driver from +Donald Becker's site: + + ftp://cesdis.gsfc.nasa.gov/pub/linux/drivers/test/eepro100.c + +There was a reported problem on the Z505SX that if the ethernet +interface is disabled and reenabled while the sound driver is loaded, +the machine would lock up. I have included a workaround that is +working satisfactorily. However, you may occasionally see a message +about "Releasing interrupts, over 1000 bad interrupts" which indicates +that the workaround is doing its job. + +================================== +PCMCIA and the Z505S/Z505SX/Z505DX +================================== + +There is also a known problem with the Sony Z505S and Z505SX hanging +if a PCMCIA card is inserted while the ethernet driver is loaded, or +in some cases if the laptop is suspended. This is caused by tons of +spurious IRQ 9s, probably generated from the PCMCIA or ACPI bridges. + +There is currently no fix for the problem that works in every case. +The only known workarounds are to disable the ethernet interface +before inserting or removing a PCMCIA card, or with some cards +disabling the PCMCIA card before ejecting it will also help the +problem with the laptop hanging when the card is ejected. + +One user has reported that setting the tcic's cs_irq to some value +other than 9 (like 11) fixed the problem. This doesn't work on my +Z505S, however--changing the value causes the cardmgr to stop seeing +card insertions and removals, cards don't seem to work correctly, and +I still get hangs if a card is inserted when the kernel is booted. + +Using the latest ethernet driver and pcmcia package allows me to +insert an Adaptec 1480A SlimScsi card without the laptop hanging, +although I still have to shut down the card before ejecting or +powering down the laptop. However, similar experiments with a DE-660 +ethernet card still result in hangs when the card is inserted. I am +beginning to think that the interrupts are CardBus-related, since the +Adaptec card is a CardBus card, and the DE-660 is not; however, I +don't have any other CardBus cards to test with. + +====== +Thanks +====== + +First, I want to thank everyone (except NeoMagic of course) for their +generous support and encouragement. I'd like to list everyone's name +here that replied during the development phase, but the list is +amazingly long. + +I will be rather unfair and single out a few people, however: + + Justin Maurer, for being the first random net.person to try it, + and for letting me login to his Z505SX to get it working there + + Edi Weitz for trying out several different versions, and giving + me a lot of useful feedback + + Greg Rumple for letting me login remotely to get the driver + functional on the 256ZX, for his assistance on tracking + down all sorts of random stuff, and for trying out Accel-X + + Zach Brown, for the initial AC97 mixer interface design + + Jeff Garzik, for various helpful suggestions on the AC97 + interface + + "Mr. Bumpy" for feedback on the Z505RX + + Bill Nottingham, for generous assistance in getting the mixer ID + code working + +================= +Previous versions +================= + +Versions prior to 0.3 (aka `noname') had problems with weird artifacts +in the output and failed to set the recording rate properly. These +problems have long since been fixed. + +Versions prior to 0.5 had problems with clicks in the output when +anything other than 16-bit stereo sound was being played, and also had +periodic clicks when recording. + +Version 0.7 first incorporated support for the NM256ZX chipset, which +is found on some Dell Latitude laptops (the CPt, and apparently +some CPi models as well). It also included the generic AC97 +mixer module. + +Version 0.75 renamed all the functions and files with slightly more +generic names. + +Note that previous versions of this document claimed that recording was +8-bit only; it actually has been working for 16-bits all along. |
