- Call isa_dmadone() whenever necessary to stop DMA and/or free bounce
buffers. Undead DMA corrupted the malloc freelist fairly consistently
in the following configuration: SLICE kernel, 2 floppy drives, no disk
in fd0, disk in fd1.
- Don't call fdc_reset() from fd_timeout(). Doing so gave an "extra"
interrupt which was usually misinterpreted as being for completion
of the next FDC command; the interrupt for completion of the next
FDC command was then usually misinterpreted... There were further
complications for interrupts latched by the soft-spl mechanism so
that they were delivered after all the h/w interrupts went away.
This caused at least wrong head settle delays and may be why the
FreeBSD floppy driver seems to munch floppies more than most floppy
drivers. The reset was unnecessary anyway in cases that didn't have
the bug described next, since is was repeated a little later for
the IOTIMEDOUT state. The state machine has complications to handle
resets correctly, so just use it.
- Don't call retrier() from fd_timeout(). The IOTIMEDOUT state needs
to be processed next, and it isn't valid to set to that state if
retrier() has aborted the current transfer. Doing so caused null
pointer panics after the previous bug was fixed.
Improved error handling:
- If an i/o is aborted, arrange to reset in the state machine before
doing the next i/o. New fdc flag for this. This fixes spurious
warnings and lengthy busy-waiting for the next i/o.
- Split STARTRECAL into RESETCOMPLETE and STARTRECAL and only check
for the results from reset if we actually reset. This fixes spurious
warnings for other paths to STARTRECAL. [Oops, it may break reset
handling for motor-off resets.]
Cleanups in fd_timeout():
- Renamed to fd_iotimeout() to make it clearer that it is only used
for i/o.
- Don't handle the bp == 0 case. This case can't happen for i/o.
- Don't check for controller-busy. We know it must be.
- Don't print anything. retrier() already prints too much for normal
errors.
- Fudge the state differently so that the state machine advances
fdc->retry and the status is invalid (perhaps this should fudge a
valid state like the one for WP).
- Style fixes.
number of dma overruns/underruns for systems under heavy dma load.
As a side effect, broken enhanced floppy controllers that sometimes
don't detect dma overruns/underruns will give less errors.
Reviewed by: j@uriah.heep.sax.de (J Wunsch)
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
floppy driver (or in the hardware?). It turned out to be caused by
spurious interrupts, right after an FDC reset.
Also major cleanup in the low-level structure, there are now functions
performing error-checks for the FDC I/O.
Submitted by: (mostly) Peter Dufault <dufault@FreeBSD.org>
date: 1994/05/22 12:35:38; author: joerg; state: Exp; lines: +6 -6
First round of floppy changes. Try making `fd' more robust.
New features:
. ioctl command for setting the drive type (density etc.); restricted
to the super-user
. ioctl for getting/seting `drive options'; currently only option
is FDOPT_NORETRY: inhibit the usual retries; used when verifying
a newly formatted track
Fixes:
. function prototypes
. made all internal functions `static'
. cleaned up & corrected .h files
. restructured, to make the chaotic function sequence more rational
. compiled with -Wall, and cleared all warnings
. introduced a mirror for the (write-only) `digital output register',
to avoid the current kludge
. device probing completed by seeking/recalibrating, and looking
for track 0 being found
. holding the controller down in reset state while it is idle (and
thus saving allot of headaches)
. make requests fail that are not a multiple of the (physical)
sector size
. removed the fixed physical sector size (512 bytes), allowing for any
size the controller could handle (128/256/512/1024 bytes)
. replaced some silly messages
. fixed the TRACE* macro usage, debugging reports should be complete
now again (debugging output is HUGE! though)
. removed fd_timeout for SEEK command; seeks are always reported by
the controller to succeed, since the `success' only refers to the
controller's idea of success - there is no hardware line to tell about
the seek end (other than the `track 0' line)
. catch SENSEI's that report about a `terminated due to READY changed'
status - could happen after a controller reset
. converted ``hz / <something>'' divide operations to divisors that are
powers of two, so gcc can optimize them into shifts
. write/format operations are checked against a write-protected medium
now *prior* starting the operation
. error reports of `invalid command' and `wrong cylinder' will cause
shortcuts in the retrier() now
. fixed a bug in the retrier() causing bogus block numbers to be reported
. fdformat() does care for errors now
Known Bugs:
. no attempts have been made (yet) to improve the performance
. sometimes, bogus ``seek/recalib failed'' messages are logged; this
is still a bug in the driver, but it's not harmful since it's
usually caught by the retrier()
Reviewed by:
Submitted by:
Obtained from:
