Robert Hancock wrote:
I've been working on the patch for sata_nv ADMA support for nForce4 that
Jeff Garzik has in a git branch. I've gotten it into a state where the
ADMA and NCQ features appear to be working with no obvious problems.
I've attached a patch against 2.6.18-mm2.
The code was mostly in a working state for the non-NCQ case but there
were a number of heinous bugs that prevented NCQ from working, like in
the sg list to APRD conversion code and in the interrupt handler.
This is still in quite an experimental state. It has survived system
boots into Fedora Core 5 and Bonnie++ benchmark runs without blowing up,
but there could still be bugs that could corrupt data, etc. so test with
caution.
There is a module parameter adma_enabled which has to be set to 1 to
enable ADMA on CK804/MCP04 chipsets (either that or hack the code to
make the default 1). I only enabled ADMA on those chipsets and not
MCP51, MCP55 or MCP61 since that was all that the original NVIDIA
version did. I assume there was a reason for this, though maybe not.
Someone with one of these chipsets should probably try it out (replacing
the GENERIC type with CK804 in the PCI device table may be all it takes).
Nice! Good work.
A few outstanding issues:
-Error handling likely needs work. EH works well enough to get past
drive detection but that's likely about all. When I ran into errors
while debugging, it usually locked up the machine when trying to do a
soft reset.
-Error handling is also noisy at the moment (it dumps a bunch of
controller state information).
-Jeff will probably cringe at how I implemented the
bmdma_stop/start/status/setup functions. This kludge of toggling
ATA_FLAG_MMIO off for the call into libata was needed since this
controller is almost what libata calls ATA_FLAG_MMIO, but not quite (the
ATA taskfile registers are MMIO but the BMDMA registers are PIO). This
is also why I needed the patch to libata-sff.c to use the adapter's
bmdma_status function rather than hardcoded ata_bmdma_status.
*shrug* I don't cringe if that's the most expedient way to do something.
But I really don't think that is necessary. I will take a look at docs
and see how things match up, when I am much more awake. Most likely you
need to be using another set of registers, and be all MMIO, all the time.
Jeff
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