From: David Laight > Transfer requests for usb disks can contain a large number of 4k fragments. > Assume that it doesn't matter if there are LINK TRB in fragment lists > that are 1k aligned. > > This should stop errors when transfer requests for usb disks contain > more fragments that will fit in a ring segment. > > Signed-off-by: David Laight <david.laight@xxxxxxxxxx> > --- > Note that this patch just allows large numbers of aligned fragments for > bulk scatter-gather transfers. > It doesn't remove the need for the patch that changes the way the ownership > of the the first TRB is set in order to avoid the controller seeing 'dangling' > LINK TRBs. > However it does reduce the likelyhood of dangling LINK TRBs, so might seem to > make the other patch unnecessary. > > I've only compile tested it - but it should be fine. Tested with aligned transfers for a usb memory stick and unaligned ones for ethernet. I failed to generate more than 30 sg entries. Interestingly the disk transfers (eg from dd bs=1M) are pairs of 122880 (15 * 8192) and 8192 bytes. Seems suboptimal! David -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
