This gives +10% performance on simple tests, so definitly worth it.
A few percent more could be had by not using M_ZERO'd alloc's, but
we then need to clear fields all over the place to be safe, and
that was deemed not worth the trouble (and it makes life dangerous).
of the leftovers from the old version that really doesn't work anymore.
Add a reset function for host-end of the ATA channel. This is needed
for the SiI3112 in order to whack it back to reality if a device
locks up the SATA interface (thereby preventing that we can reset the
device). The result is that ATA now recovers from the timeouts that
happens with the SiI3112A and more or less all disks based on old
PATA electronics with a Marvell PATA->SATA converter. This includes
lots of the popular SATA dongles and the WDC Raptor disks..
Serialize access to the SATA channels, the chip messes up if
both channels are used at the same time.
The SiI3112 hereby takes the price as the most crappy SATA chip in
existance by a significant amount.
My advise to our userbase is to avoid this chip like the plague...
Setup decent transfer mode defaults as some BIOS's seem to put in
things that it *knows* doesn't work.
(Note to BIOS writers: stop doing that nonsense, we will get things
working with your crappy HW anyways, and then recommend users to buy
someone else's products that "just works", thankyou.. )
Limit the device transfer mode to ATA100/UDMA5 on generic SATA.
Since we dont know if the user is using a pure SATA device or an
old PATA drive with a SATA converter dongle, we need to limit the
speed used here to cover up the problems with Marvell ATA-SATA bridges
used in lots of SATA products.
This workaround is enabled for all detectable SATA controllers as they
seem to have semilar problems here. One notable exception is all the
Promise pdc2037x chips which just always work (cudos to Promise!).
The altio resource magic no longer worked probably due to other changes
in the kernel. Redo that part so it also fits better into ATAng.
Fix detach so it doesn't panic the system when a pccard device is
yanked.
Approved by: re@
TOC's for the same media!! that borks up GEOM.
Although this looks like bad HW the following patch removes the
chance for GEOM panic'ing.
Approved by: re@
Add a sysctl declaration for hw.ata.atapi_dma, which had gone MIA (though
setting it in loader.conf still worked, it was not visible at runtime)
Approved by: sos
GEOM was not designed to handle media that does not have
a size. Blank CD's are of that type, so cheat and set the
media size to -1. This allows burning to work, but makes
GEOM issue outofrange reads that makes the ATAPI subsystem
spew out a few warnings. GEOM should be tought about this.
GEOM was not designed to handle changing the sectorsize
between opens. Writing multitack CD's with both audio and
data tracks needs to change sector size on the fly. We
cheat here and stuff the current sectorsize into GEOM
private internals. GEOM should grow some clean way for this.
in connection with Marvell based SATA->PATA dongles.
The problem was caused by a combination of things working
together to make it hard to spot...
The ATA driver has always started the ATA command, then build
the SG list for DMA and then finally started the DMA engine.
While this is according to specs, it poses a potential
problem as some controllers apparently do not allow for unlimitted
time between starting the ATA command and starting the DMA engine.
At about the same time as ATAng was committed there were lots
of other changes applied, some of which was locking in parts
that causes the busdma load functions to take significantly
longer to load the SG list.
This pushed the time spent between starting the ATA command and
starting the DMA engine over the hill for some controllers
(especially the Silicon Image DS3112a) and caused what looked
like lost interrupts.
The solution is to get all the SG list work or rather all
busdma related stuff done before we even try to start anything.
This has the nice side effect of seperating busdma out the
way it should be, so the working of the ATA machinery is not
cluttered up with busdma droppings, making the code easier
to read and understand.
