On Wed, Nov 19 2003, James Bottomley wrote: > On Wed, 2003-11-19 at 07:04, Jens Axboe wrote: > > On Wed, Nov 19 2003, Oliver Neukum wrote: > > > > > > > > You could add a scsi_host fields or bits specifying alignment > > > > > restrictions, and enforce them as needed in upper level drivers. > > > > > > > > The queue already has such a restriction embedded, see bio_map_user() > > > > and queue_dma_alignment(). > > > > > > Very well, as far as sd and sr are concerned, but it doesn't help for > > > sg and st, does it? > > > > They both have a queue through the scsi device structure. But you could > > put the value someplace else if you wanted. > > Actually, the sg case should be fine, because it shares the queue with > the other attachment (unless it's a processor or other unrecognised > device). > > but, regardless, the queue is already set up (for all devices, including > st) in either slave_alloc, or slave_configure, so you could call the > alignment setting routine there.
That was my point, yes. > Alternatively, we could add this as yet another parameter to the host > and template structures. Any preferences? I suppose you have to, if you want LLD to be able to pass it down. -- Jens Axboe ------------------------------------------------------- This SF.net email is sponsored by: SF.net Giveback Program. Does SourceForge.net help you be more productive? Does it help you create better code? SHARE THE LOVE, and help us help YOU! Click Here: http://sourceforge.net/donate/ _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
