-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 While looking into implementing the START STOP UNIT SCSI command for SATA disks, I spent some time looking at power management state machines in various standards. It is pretty confusing stuff so I have made a web page to summarise the various states. See: http://www.torque.net/sg/power.html One linux (or device) problem I noticed while looking at this was how lk 2.6.13-rc6 reacts when an ATAPI cd/dvd drive is placed into SLEEP state. This isn't a normal thing to do but can be done thus: sg_start -pc=5 /dev/hdd where sg_start is found in the sg3_utils package. The ATA8-ACS draft says that the device should first respond to a SLEEP ATA command and thereafter not respond to any commands until a reset occurs. One would think that the MMC equivalent (i.e. START STOP UNIT command [power_condition=5]) should react the same way. What I observed on my laptop was about 10 minutes of timeouts (with a message about lost interrupts every minute) before things stabilised. Same thing occurred on a desktop with a recent LG DVD+-R DL drive. I don't think kscd polling the drive was helping. Doug Gilbert -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iD8DBQFC+u8unayo+9E+FQIRAknJAJ9wGSGIuhK7Hhd5gTd4bIj08GD+jACgovDm q+/tSP5uo2LIFbQwENqc2j4= =43KH -----END PGP SIGNATURE----- - : 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
