1) Don't wait for DRQ on an IDENTIFY command -- if it's not set when we see
BSY clear, abort the command and ignore the drive. (Do this by testing
for DRQ in the read/write cases in __wdccommand_intr().)
2) Don't wait for DRQ to deassert when we finish an IDENTIFY (or any other
non-block command that reads data) -- we don't do this for block I/O, and
empirically it doesn't clear on my CF cards at all, causing a pointless 1s
delay.
3) Add comments to some of the delay()s, and add missing ones in wdcreset()
and the WDCC_RECAL in the so-called "pre-ATA" probe.
4) Slightly simplify the reset sequence -- we were doing an extra I/O.
5) Modify the register writability test to make sure that registers are not
overlapped -- this can happen in some weird cases with a missing device 1.
6) Check the error register value after the reset -- if it's not 01h or 81h,
as appropriate (see ATA spec), punt.
Tested with a number of ATA-only, ATAPI-only, mixed ATA-ATAPI, CF, and IDE
disk configurations.
Also remove the SINGLE_DRIVE nonsense again.
the data transfer. This is mandatory for data out commands (although none are
used for now), and not forbiddend for data in commands. Also record if we
did transfers any data.
May solve kern/16159 by making the probe more robust in face of fake identify.
- move some functions from ata.c to ata_wdc.c or wdc.c.
- add callbacks to struct ata_bustype so that wd.c doesn't call directly
functions from the lower level driver.
- 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 ...
DRIVE_OLD, DRIVE_ATA or DRIVE_ATAPI based on register signatures.
The attach routine will issue a IDENTIFY command for ATA/ATAPI disk,
to detect flase matches by the probe routine.
probe/attach should now be fully compliant with ata-4/ata-5. As a side
effect, ATAPI drives which improperly use ATA register signatures should now
be attached as ATAPI.
the disk is ready to transfer data, and in ATA-5 the DSC has been obsoleted.
So only wait for DRQ to transfer data. This can be made conditional on the
ATA version if it's proven to break with some drives (worked with all the
drives I have access to).
While I'm there correct a few typos.
In wdc_probe_caps() add code to guess the ATA revision supported (if
ATA4 if Ultra-DMA, ATA2 if PIO mode > 2). We can't rely on param.atap_ata_major
here, at last one Ultra-DMA drive claims to support only ATA-3.
Use the ATA version in ata_perror(), and to try a flush cache command
in a shutdown hook for IDE drives.
mycroft