Commit Graph

6 Commits

Author SHA1 Message Date
Poul-Henning Kamp
1b67be7b75 Rewrite of the floppy driver to make it MPsafe & GEOM friendly:
Centralize the fdctl_wr() function by adding the offset in
	the resource to the softc structure.

	Bugfix: Read the drive-change signal from the correct place:
	same place as the ctl register.

	Remove the cdevsw{} related code and implement a GEOM class.

	Ditch the state-engine and park a thread on each controller
	to service the queue.

	Make the interrupt FAST & MPSAFE since it is just a simple
	wakeup(9) call.

	Rely on a per controller mutex to protect the bioqueues.
	Grab GEOMs topology lock when we have to and Giant when
	ISADMA needs it.  Since all access to the hardware is
	isolated in the per controller thread, the rest of the
	driver is lock & Giant free.

	Create a per-drive queue where requests are parked while
	the motor spins up.  When the motor is running the requests
	are purged to the per controller queue.  This allows
	requests to other drives to be serviced during spin-up.

	Only setup the motor-off timeout when we finish the last
	request on the queue and cancel it when a new request
	arrives.  This fixes the bug in the old code where the motor
	turned off while we were still retrying a request.

	Make the "drive-change" work reliably.  Probe the drive on
	first opens.  Probe with a recal and a seek to cyl=1 to
	reset the drive change line and check again to see if we
	have a media.

	When we see the media disappear we destroy the geom provider,
	create a new one, and flag that autodetection should happen
	next time we see a media (unless a specific format is configured).

	Add sysctl tunables for a lot of drive related parameters.
	If you spend a lot of time waiting for floppies you can
	grab the i82078 pdf from Intels web-page and try tuning
	these.

	Add sysctl debug.fdc.debugflags which will enable various
	kinds of debugging printfs.

	Add central definitions of our well known floppy formats.

	Simplify datastructures for autoselection of format and
	call the code at the right times.

	Bugfix: Remove at least one piece of code which would have
	made 2.88M floppies not work.

	Use implied seeks on enhanced controllers.

	Use multisector transfers on all controllers.  Increase
	ISADMA bounce buffers accordingly.

	Fall back to single sector when retrying.  Reset retry count
	on every successful transaction.

	Sort functions in a more sensible order and generally tidy
	up a fair bit here and there.

	Assorted related fixes and adjustments in userland utilities.

WORKAROUNDS:
	Do allow r/w opens of r/o media but refuse actual write
	operations.  This is necessary until the p4::phk_bufwork
	branch gets integrated (This problem relates to remounting
	not reopening devices, see sys/*/*/${fs}_vfsops.c for details).

	Keep PC98's private copy of the old floppy driver compiling
	and presumably working (see below).

TODO (planned)

	Move probing of drives until after interrupts/timeouts work
	(like for ATA/SCSI drives).

TODO (unplanned)

	This driver should be made to work on PC98 as well.

	Test on YE-DATA PCMCIA floppy drive.

	Fix 2.88M media.

This is a MT5 candidate (depends on the bioq_takefirst() addition).
2004-08-20 15:14:25 +00:00
Poul-Henning Kamp
8a1f37f227 PC98 got it right here: sectors can be non-512 byte sized. 2004-07-07 20:28:31 +00:00
Yoshihiro Takahashi
1a06a03cb8 Add PC98 supports.
Submitted by:	Watanabe Kazuhiro <CQG00620@nifty.ne.jp> (mostly)
2004-03-28 13:42:27 +00:00
Poul-Henning Kamp
9cee00cf10 Set size field correctly, it is number of sectors on the device, not
number of 512 bytes sectors.

Recognize size == -1 as meaning "auto".
2004-02-25 13:43:17 +00:00
Joerg Wunsch
1a6bed6863 Long promised major enhancement set for the floppy disk driver:
. The main device node now supports automatic density selection for
  commonly used media densities.  So you can stuff your 1.44 MB and
  720 KB media into your drive and just access /dev/fd0, no questions
  asked.  It's all that easy, isn't it? :)

. Device density handling has been completely overhauled.  The old way
  of hardwired kernel density knowledge is no longer there.  Instead,
  the kernel now implements 16 subdevices per drive.  The first
  subdevice uses automatic density selection, while the remaining 15
  devices are freely programmable.  They can be assigned an arbitrary
  name of the form /dev/fd[:digit]+.[:digit:]{1,4}, where the second
  number is meant to either implement device names that are mnemonic
  for their raw capacity (as it used to be), or they can alternatively
  be created as "anonymous" devices like fd0.1 through fd0.15,
  depending on the taste of the administrator.  After creating a
  subdevice, it is initialized to the maximal native density of the
  respective drive type, so it needs to be customized for other
  densities by using fdcontrol(8).  Pseudo-partition devices (fd0a
  through fd0h) are still supported as symlinks.

. The old hack to use flags 0x1 to always assume drive 0 were there is
  no longer supported; this is now supposed to be done by wiring the
  devices down from the loader via device flags.  On IA32
  architectures, the first two drives are looked up in the CMOS
  configuration records though.  On PCMCIA (i. e., the Y-E Data
  controller of the Toshiba Libretto), a single drive is always
  assumed.

. Other specialities like disabling the FIFO and not probing the drive
  at boot-time are selected by per-controller or per-drive flags, too.

. Unit attentions (media has been changed) are supposed to be detected
  now; density autoselection only occurs after a unit attention.  (Can
  be turned off by a per-drive flag, this will cause each Fdopen() to
  perform the autoselection.)

. FM floppies can be handled now (on controllers that actually support
  it -- not all do these days).

. Fdopen() can be told to avoid density selection by setting
  O_NONBLOCK; this leaves the descriptor in a half-opened state where
  only a few ioctls are accepted.  This is necessary to run fdformat
  on a device that uses automatic density selection (since you cannot
  autoselect on an unformatted medium, obviously).

. Just differentiate between a plain old NE765 and the enhanced chips,
  but don't try more; the existing code was wrong and only misdetected
  the chips anyway.

BUGS and TODOs:

. All documentation update still needs to be done.

. Formatting not-so-standard format yields unpredictable results; i
  have yet to figure out why this happens.  "Standard" formats like
  720 and 1440 KB do work, however.

. rc scripts are needed to setup device nodes with nonstandard
  densities (like the old /dev/fdN.MMM we used to have).

. Obtaining device flags from the kernel environment doesn't work yet,
  thus currently only drives that are present in (IA32) CMOS are
  really detected.  Someone who knows the odds and ends about device
  flags is needed here, i can't figure out what i'm doing wrong.

. 2.88 MB still needs to be done.
2001-12-15 19:09:04 +00:00
Joerg Wunsch
65217f13ff Break out the function to print the FDC error information into
fdutil.c so it can be used elsewhere.
2001-07-02 21:21:58 +00:00