2009/12/14 Janos Haar <janos.haar@xxxxxxxxxxxx>: > Hello, > > ----- Original Message ----- From: "Robert Hancock" <hancockrwd@xxxxxxxxx> > To: "Janos Haar" <djani22@xxxxxxxxxxxx> > Cc: <linux-kernel@xxxxxxxxxxxxxxx> > Sent: Tuesday, December 15, 2009 2:02 AM > Subject: Re: HDD power up in standby > > >> On 12/14/2009 04:22 AM, Janos Haar wrote: >>> >>> Hello list, >>> >>> I have posted to the common, because this theme is for more lists (ide, >>> sata, scsi), i think.... >>> >>> I know you will not like me guys, but i have one wish.... :-) >>> >>> I am building cheap but big storages, and after 12 drive / PC i have >>> faced >>> with one problem: >>> The too much spinup current wich made by the 12-16 drive at the same >>> time. >>> In my actual case, in 12V, there is more than 2A / drive for some >>> seconds. >>> >>> I know, in SCSI, there is a jumper for this, and the card can wake up the >>> drives one by one, but i am using 2TB drives, and in SCSI/SAS this have >>> horrible price... >>> I have done some invesrtigation, and found this: >>> The most of the simple sata drives handles the PUIS mode (by set >>> features ata command), but unfortunately >>> only the professional and expensive raid cards supports the wakeing up. >>> If the cheap cards founds only 0 byte drives, this is not a problem at >>> all, >>> because linux usually not use BIOS support fortunately. :-) >>> But i have found when i have spent a little time in google, and in the >>> documentation, linux doesn't support PUIS. >>> >>> I think this would be great, and (relatively) simple to implement this >>> feature. >>> I can imagine in this way: >>> Wake up from PUIS is disabled by default, but can be enabled by command >>> line >>> parameter, or compile time configuration. >>> The drivers should send the wake up command one by one to the drives, >>> waits >>> for RDY DSC, and than scan the drives, and register.... >>> >>> What do you think? >> >> As far as I can see, if the drive reports it's in power-up in standby mode >> from the identify response, the kernel will send the command to spin up the >> drive. It might depend on whether parallel scan is enabled for the >> controller as far as whether they actually spin up one at a time, however. > > I am working with 2TB Hitachi drive wich is set to PUIS, and reports itself > as 0 byte, but existing device (pcb factory alias), but with my promise > card, the kernel see only bad geometry and disable the port only. :-( > I have missed something? Can you post the full boot log? -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
