Jeff Garzik wrote:
Currently, libata creates a Scsi_Host per port. This was originally done to leverage SCSI's infrastructure to arbitrate among master/slave devices, but is not needed for most modern SATA controllers. And I _think_ it is not needed for master/slave if done properly, either.
BTW note the above, with regards to the libata SCSI->block conversion. libata currently relies on SCSI for some amount of generic device arbitration, in several situations (see ->qc_defer, SCSI_MLQUEUE_.*_BUSY). libata expects SCSI to be intelligent and not starve devices, etc.
I was able to successfully boot the following patch on AHCI/x86-64/Fedora. It may work with other controllers -- TRY AT YOUR OWN RISK. It will probably fail for master/slave configurations, and SAS & PMP also need looking at. It yielded this lsscsi output on my AHCI box: [0:0:0:0] disk ATA ST3500320AS SD15 /dev/sda [0:2:0:0] disk ATA G.SKILL 128GB SS 02.1 /dev/sdb [0:5:0:0] cd/dvd PIONEER BD-ROM BDC-202 1.04 /dev/sr0
For comparison, here is unmodified 2.6.30-rc3: [jgarzik@bd ~]$ lsscsi [0:0:0:0] disk ATA ST3500320AS SD15 /dev/sda [2:0:0:0] disk ATA G.SKILL 128GB SS 02.1 /dev/sdb [5:0:0:0] cd/dvd PIONEER BD-ROM BDC-202 1.04 /dev/sr0 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
