Messages in this thread | | | Date | Thu, 25 Oct 2001 12:02:15 +0200 | From | Helge Hafting <> | Subject | Re: [RFC] New Driver Model for 2.5 |
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Rob Turk wrote:
> Doing so will create havoc on sequential devices, such as tape drives. If > your system simply suspends, then all is well. Any data that isn't flushed > yet is buffered inside the tapedrive. But when the system resumes and resets > the SCSI bus, it will cause all data in the tape drive to be lost, and for > most tape systems it will also re-position them at LBOT. Any running > tar/dump/whatever tape process would not survive such a suspend-resume > cycle. > Well, why reset the scsi bus on resume then? That seems unnecessary. At suspend time the devices simply don't get more requests. (Except perhaps spin-down requests for disks.) Then nothing much happens. Eventually the system wakes up, and requests appear again. First spin-up requests, then ordinary io.
Quite a few scsi bioses have an option for not resetting the bus when booting. Less delay, and necessary for those few with a shared scsi bus. Seems a reset won't be necessary for suspend/resume either, which is supposed to be a lighter operation than a reboot.
If your scsi adapter don't support this - it isn't suspend/resume compatible the way I see it.
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