Re: linux: sata_nv: adma support

[Mark Lord <kernel@start.ca>]

On 15-08-01 09:45 PM, Robert Hancock wrote:
> On Sat, Aug 1, 2015 at 2:09 PM, Pali Rohár <pali.rohar@gmail.com> wrote:
>> On Thursday 25 December 2014 07:22:13 Robert Hancock wrote:
>>> On Tue, Dec 23, 2014 at 1:51 PM, Pali Rohár <pali.rohar@gmail.com>
>>> wrote:
>>>> Hello,
>>>>
>>>> I have nvidia nforce4 motherboard with nvidia sata controller:
..
>>> It looks like something is trying to issue a command to disable APM
>>> power management on the drive, and the command fails (likely because
>>> it doesn't support that command).
..
>>   /sbin/hdparm -B254 $DRIVE
>>
>> And that -B254 cause above error message in dmesg log. Output from
>> hdparm is:
>>
>>   /dev/sda:
>>    setting Advanced Power Management level to 0xfe (254)
>>    APM_level      = not supported
..
>>   $ sudo hdparm -I /dev/sda | grep -i power
>>              *    Power Management feature set

That's not the same as APM ("Advanced" Power Management).

> However, these NVIDIA SATAs are black boxes, and rather buggy ones at that,
> so it's possible there's an unknown issue there.

I wonder if NVIDIA simply bought out the IP from Pacific Digital
when they went bust?  Pacific Digital invented the original "ADMA",
and the pdc_adma.c driver in the kernel knows all about it.
If the IP is pretty similar (identical?) then we could probably
improve things.