On 9/6/06, Siddharth Taneja <siddharth.taneja@xxxxxxxxx> wrote:
On 9/6/06, Greg Freemyer <greg.freemyer@xxxxxxxxx> wrote: > On 9/5/06, Siddharth Taneja <siddharth.taneja@xxxxxxxxx> wrote: > > Hi, > > > > I have two SATA drives with an ICH6 SATA controller. I would like to know > > that if I were to operate the drives in PATA mode, what would happen if I > > enabled both ide/ata-piix and scsi/piix. I assume the drives would come up > > as both hda/hdb and sda/sdb. Is there a recommendation as to which device > > (or interface) to use? > > > > Also I set the bios settings for the SATA controller to AHCI and the > > ide/ata-piix driver is still able to bring up the drives as hde/hdg. Why is > > that? Shouldn't the ide/ata-piix realise that this is not a mode it > > supports? > > > > Thanks > > > > Siddharth > > > Siddharth, > > I don't know the specific answers, but this whole area is in a state of flux. > 2.6.16 likely behaves different from 2.6.17 , which is different from > 2.6.18, which will be different from 2.6.19. > > First, when multiple drivers are available for a single disk > controller, only one of them should be used. Using 2 or more can > cause huge conflicts that could easily destroy data. > > Most of the drivers are specifically written to avoid the issue. The > first driver that recognizes a disk controller claims the controller > and no other driver can claim it. In dual functionality controller > like the ICH6, I believe the 2 halves are claimed seperately. ie. The > PATA half can be controlled by drivers/ide and the SATA half can be > controlled by drivers/libata. > > That can be difficult to make work smoothly, so there is an ongoing > effort to do the below: > 2.6.18 - Greatly improved libata (SATA currently) Error Handling > 2.6.19 - Rename drivers/libata to drivers/ata as it is becoming the > main ATA driver > 2.6.19 - Add initial support for PATA drives to libata > > Thus when 2.6.19 comes out in a few months it will hopefully have the > ability to better handle these dual function controllers. It still > may require proper setup of config due to there still being multiple > drivers that support the same card. > > HTH > Greg > -- > Greg Freemyer > The Norcross Group > Forensics for the 21st Century > Thanks for your answers Greg. I think I should disable the ide/ata-piix layer and only use my drives in the libata domain as it is becoming the standard in any case. So you think libata will completely replace the drivers/ide layer? I ask this because I have another platform with two PATA drives and an ICH5 controller. Should I leave ide/piix enabled for that? (for accessing my drives in PATA mode). Or should I use the PATA functionality from the libata layer? Thanks Siddharth
There have been LKML posting explicitely stating that drivers/ide will dissappear at some point in the future, but I suspect that will be a year or two down the road. With vanilla 2.6.17/18, I don't think there is much PATA support in libata, but ICH5/6/7/8 may be special cases that are already supported in libata bacuase of their popularity and dual nature. (-mm should have had most of the PATA drivers for a couple months now, so you could try -mm if your in the mood.) As of a couple of days ago, the #upstream branch of the libata git repository had a large number of new PATA/libata drivers added to it. Alan Cox has been doing the rewrite for the last year or so. The new PATA drivers have been in -mm for testing, etc. for a while I believe and are currently slated to merge into 2.6.19 vanilla. The recommendation in general is for users/distributions to use the older drivers/ide drivers for a while yet. At some point I'm sure the new drivers will be recommended, and eventually the old ones will be deprecated, etc. You may want to be aware of http://linux-ata.org/ as a libata status page. It tends to only get updated a couple times a year, but it is better than nothing. Also, you may want to read the thread: http://marc.theaimsgroup.com/?l=linux-ide&m=115736779014037&w=2 Especially the announcement e-mail. Lots of the follow e-mails relate to dual booting between the drivers for testing. That may not have any relevance for you. HTH Greg -- Greg Freemyer The Norcross Group Forensics for the 21st Century -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
