Messages in this thread | | | Subject | Re: swsusp: don't eat ide disks | From | Alan Cox <> | Date | 04 Nov 2002 13:37:54 +0000 |
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On Mon, 2002-11-04 at 09:44, Jens Axboe wrote: > It's probably not a good idea to rely on ata drives that also speak > atapi, to my knowledge only a few old WDC drives ever did that. Since we > are basically moving to the point where "SCSI" commands is the > commandset that the block layer uses to make drivers do things for it, > I had the idea of doing a rq -> taskfile conversion for ide. Just for > simple things like read/write and sync cache, basically stuff that is > directly translatable. That would make Linus' example actually work, and > it would also make the direct read/write programs using SG_IO work on > IDE drives as well.
Going beyond IDE it might be cleaner to be able to do
struct bio_command_ops { eject: idedisk_eject, suspend: idedisk_suspend, identify: idedisk_identify, ... [maybe even read:/write: in some cases like smart scsi raids] }
that way IDE disk and all the other weirdass drives can have -one- command parser not the twenty differently buggy ones we have now simply by doing
if(rq_is_command(rq)) bio_do_command(rq, &bio_command_ops);
Its also very convenient as we can add fields to the structure and then to drives without breaking the API and without so much updating
Alan
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