http://mail-index.netbsd.org/tech-kern/2003/09/25/0006.html
This adds a device (atabus) between IDE controllers and wd or atapibus, to
have each ATA channel show up in the device tree. Later there will be atabus
devices in /dev, so that we can do IOCTL on them.
Each atabus has its own kernel thread, to handle operations that needs polling,
e.g. reset and others.
Device probing on each bus it defered to the atabus thread creation.
This allows to do the reset and basic device probes in parallel, which reduce
boot time on systems with several pciide controllers.
most polling.
2) Clean up some goofiness in pciide -- get rid of the whole "candisable" path
(it's gratuitous) and simplify the code by calling pciide_map_compat_intr(),
*_set_modes() and wdc_print_modes() from central locations.
3) Add a register writability and register ghost test to eliminate phantom
drives more quickly.
the "bus type" for this.
Merge all the code in the SCSI and ATAPI backends for "cd" devices. All of
the mode page handling and whatnot is general to SCSI MMC devices, and should
never have been separated to begin with. This fixes a variety of problems,
and adds load/unload support for SCSI-attached devices.
deal with such xfers, and can wedge the system with some controllers.
It's a bug to request such xfers for ATAPI, but as the request may come
from userland we have to protect against it.
all function pointers passed in from the adapter driver.
This partly fixes PR 13480, i.e. the FREECOM CD driver works now in pcmcia
adapters.
The remaining issue (timing problems with slow cards and cardbus bridges)
is probably the cause of several other PRs too.
kill ata_atapi_attach. Change atapibus to use a struct scsipi_channel instead
of ata_atapi_attach as attach arch. Create a ata_device, compatible with
scsipi_channel, to attach wd.
This is a completely rewritten scsipi_xfer execution engine, and the
associated changes to HBA drivers. Overview of changes & features:
- All xfers are queued in the mid-layer, rather than doing so in an
ad-hoc fashion in individual adapter drivers.
- Adapter/channel resource management in the mid-layer, avoids even trying
to start running an xfer if the adapter/channel doesn't have the resources.
- Better communication between the mid-layer and the adapters.
- Asynchronous event notification mechanism from adapter to mid-layer and
peripherals.
- Better peripheral queue management: freeze/thaw, sorted requeueing during
recovery, etc.
- Clean separation of peripherals, adapters, and adapter channels (no more
scsipi_link).
- Kernel thread for each scsipi_channel makes error recovery much easier
(no more dealing with interrupt context when recovering from an error).
- Mid-layer support for tagged queueing: commands can have the tag type
set explicitly, tag IDs are allocated in the mid-layer (thus eliminating
the need to use buggy tag ID allocation schemes in many adapter drivers).
- support for QUEUE FULL and CHECK CONDITION status in mid-layer; the command
will be requeued, or a REQUEST SENSE will be sent as appropriate.
Just before the merge syssrc has been tagged with thorpej_scsipi_beforemerge
if an IRQ was not detected, unless the force flag was given. Use this to
detect if the IRQ was for us (closer to shared IRQ for controllers which
don't have their own IRQ handler in pciide.c) and to poll for DMA xfer.
Also makes the timeout recovery code simpler.
- ATAPI cleanup: don't call controller-specific functions from atapiconf.c
(wdc_*), so that it's possible to attach an atapibus to something else
than a wdc/pciide (Hi Lennart :).
Overload struct scsi_adapter with struct atapi_adapter, defined
as struct scsi_adapter + atapi-specific callbacks. scsipi_link still points
to an scsi_adapter, atapi code casts it to atapi_adapter if needed.
Move atapi_softc to atapiconf.h so that it can be used by the underlying
controller code (e.g. atapi_wdc.c).
Add an atapi-specific callback *atapi_probedev(), which probe a drive
in a controller-specific way, allocate the sc_link and fills in the
ataparams if needed. It then calls atapi_probedev() (from atapiconf.c)
to do the generic initialisations and attach the device.
- While I'm there merge and centralise the state definitions in atavar.h.
It should now be possible to use a common ata/atapi routine to set the
drive's modes (will do later).
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.
The old timeout()/untimeout() API has been removed from the kernel.
- If UDMA 2 is failing try UDMA 1 first, it helps in some cases
- downgrade if we get an error in the first 4000 xfers, or if we get
4 errors in 4000 xfers if the first 4000 went without troubles.
While I'm there commit a local change I have since some time to get my CD
probed: issue a "blanck" IDENTIFY before the one used to detect slave ghosts,
with my drive the first IDENTIFY following a controller reset fails with an
aborted command ...
- `flags' is now gone, replaced with `xs_control' and `xs_status'.
- Massive cleanup of the control flags. Now we explicitly say that
a job is to complete asynchronously, rather than relying on side-effects,
and use a new flag to now that device discovery is being performed.
- Do SCSI device discovery interrupt-driven.
2 times in the past
- Set up timeout per xfer instead of per interrupt. This helps with
PIO transfer (we would call timeout()/untimout() several times for a
transfer).
- If we missed an interrupt for a PIO transfer, reset and restart it
immedialy, don't try to recover and continue. If we missed an interrupt we
may have lost a read/write cycle on the IDE bus. If this happens 1) we
corrupt data and 2) we enter an interrupt loop at the end of the xfer, as
the drive has some more data to read/write, but the host thinks the xfer is
done.
This last change fix the (or at last some of the) 'lookup after lost interrupt'
some peoples have been experiencing.
By code inspection I found 2 bugs in the ATAPI code, one may be the cause
of your problem: A counter is not reset when issuing the request_sense
command. This is c_skip, the counter used to track the offset in the data
buffer when a data tranfer needs multiple phases. The effect of this is that
the sense data transfered may be stored outside the sense buffer (sense buffer
+ some, potentially several KB, offset). This can only occur in PIO mode,
DMA is not affected.
This doesn't occur in "normal" use because when reading a data CD, either
the sense is issued for a non-data command (in which case c_skip stays to
0), or an error occured and no data has been transfered, and c_skip is still 0.
I can't see a case where a data READ/WRITE could cause a sense tranfer without
error.
The second problem is that b_resid can be set to a false value (resulting of
the sense tranfer and not the data transfer). Again this is not a problem with
usual data tranfers because both values ends up being 0 when no error occurs.
EIO. The spec says ATAPI devices should support "PIO 3 or better".
They are supposed to support less as well. Setting the device to a highter
mode than the controller shoul'nt be a problem, and this is likely what
happens with legaty ISA controllers.
Solve problem reported by Ruey-Shyang Guo.
- the cap field is a u_int8_t, so none of the defined flags would fit in.
Looks like nobody had a drive using 16 bytes commands.
- the ACAP_DRQ_* flags are all wrong. Just remove them and use the definitions
from ata/atareg.h, there's no need to duplicate theses. The effect of this
was that we were always polling for the command phase, even for drives
with interrupt DRQ. This didn't break until the code was changed to support
shared interrupts.
Should fix the lookup problems or 'boot hangs' reported by some users, and
kern/7111.
are called from the interrupt or timeout handler, 0 otherwise.
- use this to know if we can busy-wait for wait_for_unbusy or wait_for_ready
This fixes a bug where CDs withot the DRQ_INTR capability would not busy-wait
for the CMDOUT phase.
While I'm there change 2 delay() to DELAY() for consistency, and
garbage-collect some old code from wdcintr() which has been ifdef'd out
for some time now.
bouyer