On 09/25/2012 10:23 PM, Oliver Neukum wrote: > On Tuesday 25 September 2012 22:20:21 Aaron Lu wrote: >> On Tue, Sep 25, 2012 at 01:47:52PM +0200, Rafael J. Wysocki wrote: >>> On Tuesday, September 25, 2012, Aaron Lu wrote: >>>> I'm thinking of enabling this GPE in sr_suspend once we decided that it >>>> is ready to be powered off, so the time frame between sr_suspend and >>>> when the power is actually removed in libata should be taken care of by >>>> the GPE. If GPE fires, the notification function will request a runtime >>>> resume of the device. Does this sound OK? >>> >>> Well, depending on the implementation. sr_suspend() should be rather >>> generic, but the ACPI association (including the GPE thing) is specific to ATA. >> >> Sorry, but don't quite understand this. >> >> We have ACPI bindings for scsi devices, isn't that for us to use ACPI >> when needed in scsi? > > We don't have ACPI bindings for generic SCSI devices. We have such > bindings for SATA drives. You can put such things only in sr if it applies > to all (maybe most) types of drives. OK. Then these scsi bindings for sata drives will be pretty much of no use I think. > >> BTW, if sr_suspend should be generic, that would suggest I shouldn't >> write any ZPODD related code there, right? Any suggestion where these >> code should go then? > > libata. Maybe some generic hooks can be called in sr_suspend(). Thanks for the suggestion. The problem is, I need to know whether the door is closed and if there is a medium inside. I've no way of getting such information in libata. > PS: Are you sure sr_suspend() handles DVD-RAMs correctly? No. Is there a spec for it? Considering there are many different drives sr handle, is it possible to write a generic sr_suspend? Maybe your suggestion of callback is the way to go. What about this idea, if we find this is a ZPODD capable drive, we enable runtime suspend for it and write a suspend callback according to ZPODD spec. For other drives that does not have a suspend callback, we do not enable runtime suspend. Does this sound reasonable? Thanks, Aaron -- To unsubscribe from this list: 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
