Documentation/sound/oss/NM256 - linux - Git at Google

 =======================================================
 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.
	=======================================================
	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.