Messages in this thread | | | From | Kay Sievers <> | Date | Fri, 16 Dec 2011 00:29:44 +0100 | Subject | Re: [RFC][PATCH 4/4] ahci: support hot plug when port/controller is runtime suspended |
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On Thu, Dec 15, 2011 at 20:21, Tejun Heo <tj@kernel.org> wrote: > On Thu, Dec 15, 2011 at 09:12:49PM +0800, Lin Ming wrote: >> I use eSATA to test disk hot plug. >> With previous 3 patches applied, disk hot plug does not wok >> when ahci port/controller is runtime suspended. >> >> There are 2 cases we need to handle for hot plug: >> >> 1. port suspended, controller active >> Is IRQ need to be enabled for port to detect hot plug? >> >> 2. port suspended, controller suspended >> Will controller get a PME when hot plug happens? >> >> I'm still investigating hot plug support. >> >> Anyone has comment? > > SATA link detection requires hot wire and keeping wire hot takes > power.
Oh, hardware in general just sucks. :)
> I think it's fair tradeoff to not support hotplug while > powersaving is on. We have warm plug mechanism (the SCSI rescan > trigger via sysfs) after all. It would be nice if things like that is > somehow exported to userland in easy way tho (cc'ing Kay), but I > frankly don't have much idea where that would fit.
Getting David in the loop. He might have an idea.
Kay -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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