Messages in this thread | | | Date | Mon, 02 Jun 2008 09:03:04 -0400 | From | Mark Lord <> | Subject | Re: [PATCH] ata: ahci: power off unused ports |
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Jeff Garzik wrote: > Alan Cox wrote: >>> If you are talking about SATA -- incorrect. >>> >>> The patch deals with policy, and the user MUST have the ability to >>> control this stuff. Otherwise you create a situation where the user >>> might be denied hotplug use in valid cases, or similar negative >>> situations. >> >> The policy isn't however complicated. Tejun added the stuff for forcing >> cable type and mode on setup and has therefore written all the per device >> setup code we might need. Alternatively a single >> >> foo=1/0 >> >> option has been fine for acpi and will do fine for this. Total additional >> cost - 1 line. > > The key requirement is per-port control. Ideally via hdparm or another > userspace tool, but kernel command line (module options) or sysfs would > be just fine too. And agreed, the minimal you need is simply 1/0 for > the port's policy. ..
Btw.. hdparm-8.7 (unreleased) can grok /sys now, so that interface is as good as any from a userspace viewpoint now.
For the power-off of unused ports, the current patch still sounds extremely vendor-specific (Intel).
Does it actually work (demonstrate, please) on any other hardware ?
I would still like to see a far more generic solution, with periodic polling and the like, which would permit use on *any* machines (eg. data centers) without loss of hotplug capability on those ports.
But that's probably just wishful thinking at this point.
Cheers
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