https://bugzilla.novell.com/show_bug.cgi?id=264681 teheo@novell.com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |NEW Info Provider|teheo@novell.com | ------- Comment #14 from teheo@novell.com 2007-04-25 10:49 MST ------- libata currently doesn't support configuring DMA settings for the following two reasons. 1. Things like that gotta be done automatically and libata is pretty good at it. 2. (admittedly more importantly) It's difficult to get right. IDE allowed it but it never was safe. Currently the biggest road block is controllers which require host-wide (cross-ports) quiescence to change transfer mode. It's scheduled to be added but priority is rather low. When it gets implemented the primary interface will be issuing SETFEATURES - SETXFERMODE using SG_IO. hdparm will probably be updated accordingly when it happens. You can tell discern libata devices among SCSI devices by examining Device identification VPD page (0x83). # sdparm --inquiry --page=0x83 /dev/sda /dev/sda: ATA WDC WD5000YS-01M 07.0 Device identification VPD page: Addressed logical unit: desig_type: vendor specific [0x0], code_set: ASCII 00 20 20 20 20 20 57 44 2d 57 4d 41 4e 55 31 32 31 WD-WMANU121 10 35 30 39 34 5094 desig_type: T10 vendor identification, code_set: ASCII vendor id: ATA vendor specific: WDC WD5000YS-01MPB0 WD-WMANU1215094 The vendor id is ATA if it's a libata device. You can access this info more easily with 'lsscsi'. # lsscsi [0:0:0:0] disk ATA WDC WD5000YS-01M 07.0 /dev/sda [1:0:0:0] disk ATA WDC WD5000YS-01M 07.0 /dev/sdb [2:0:0:0] disk ATA SAMSUNG SP2504C VT10 /dev/sdc [4:0:0:0] disk SAMSUNG HD300LD 0000 /dev/sdd However, ATA vendor ID is from SAT (SCSI-ATA translation) standard so other SAT implementations probably use it too (ATA disk attached to SAS port). But they're ATA devices too so probably can be dealt with the same way in most cases. If you really have to discern libata devices, you can issue HDIO_GET_IDENTITY ioctl to it and see whether it returns valid ATA IDENTIFY page. Sorry about the clumsy mechanism. We'll have something better when libata receives its own sysfs nodes. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is.