Initialize and limit port speed to 3 Gbps in general because the Seagate
Barracuda 1TB throws much errors with 6 Gbps by now.
Try all port speeds from the highest to the lowest as long as debouncing fails
and try them all again in this order when falling back to slower debouncing.
Try to recover from all types of interface error.
When a port was recovered from an error during a NCQ command
get the last LBA that was accessed successfully and continue command from
this point.
Use a platform driver through the 'Regulator' service to do CMU and PMU config.
Switch off verbosity by default.
* Retry debouncing first with a higher trial time and if this also doesn't
work with lower link speed additionaly.
* Ignore DevSlp feature because it isn't needed anyway as far as i can see.
* Relax some restrictions according the feedback of the drive as far as it
seem to have no effect in Linux too
Fix#753
This is a first version of the AHCI driver. It supports SATA HDDs
with UDMA-133 only, up to 6 Gbps and native command queueing.
The more blocks one transfers with one command, the higher is the
chance that the driver produces a fatal handshake error. Nevertheless
the driver is stable with one block per ATA command. Although NCQ is
used the driver doesn't queue multiple commands simultanously.
The driver was tested with a western digital HDD "WDC WD2500BEVS-08VAT1
13.01A13" (250 GB) with hw_arndale (run/ahci) and foc_arndale
(run/ahci, run/l4linux: dd). SSDs were not tested.
Fix#706
