of FIFO overflows on high baud rates.
However, doing so on all 4 ports would cost a whopping 64KB (at 4096 entries
per FIFO) of kernel memory. So, the FIFOs are now allocated at attach time
allowing the size for the keyboard and mouse ports to be reduced (to 128)
which should be adequate for the 1200 baud they use.
- properly do MSG_IN handshaking, so we can actually receive multi-byte msgs.
- do synch negotiation (now that the above works).
- handle disconnects.
There are a few trial-and-error bits at points where the docs I have are
particularly ambiguous about the state of chip and/or SCSI bus.
Things to do:
- more cleanup
- deal with MSG_OUT phase better
- keep some "config reg 3" bits per target (ie. FASTCLK and FASTSCSI).
transfer ends in stead of doing it before starting a new transfer.
Use a different CSR bit to wait for "chip not busy" (may be necessary to
make this conditional on chip revision).
- make esp_poll() approximate the given timeout value.
- introduce esp_abort(), and use it for timed out commands; make targets and driver less confused.
- make {free,ready,nexus}-list management somewhat more coherent.
- make sure we only proceed down the state machine in espintr()
if there really is an interrupt pending.
- don't let pcyl go unassigned if we have a non-sunos disklabel.
if nothing else, guess pcyl = ncyl + acyl.
- don't use bogus disklabel data if disk label is invalid
(xdgetdisklabel() now returns if label was ok or not).
- move xddriver decl. before start of actual code (cleanup).
have been clearing just B_BUSY (s/B_BUSY/~B_BUSY/). this
fixes hard hang when reading disklabel when booting system.
minor clean up: added a few prototypes and only fool with bootpath
if booting the system (in xdattach).
to match `sd' devices against the PROM's boot path.
Detect DMA "overshoots" when handling odd-sized transfer sizes (e.g., xfers
from/to raw partitions), by using the "Transfer Pad" command when the
transfer count reaches zero.
