On Wednesday 06 August 2008, Borislav Petkov wrote: > On Wed, Aug 06, 2008 at 06:05:00PM +0200, Bartlomiej Zolnierkiewicz wrote: > > > > Hi, > > > > On Tuesday 05 August 2008, Borislav Petkov wrote: > > > Hi Bart, > > > > > > here's my first stab at using scatterlists in ide-floppy. I've adapted your > > > ide-scsi version to fit in here. The change here is that i use pc->b_count as > > > a sort-of completion counter to know when i'm at the end of the sg element and > > > be able to switch to the next/finish transfer. I've tested the patch with the > > > Iomega ZIP drive i have here - it works. We should do some more testing first > > > though, before sending it upstream. > > > > [...] > > > > > @@ -569,7 +577,7 @@ static void idefloppy_create_rw_cmd(idefloppy_floppy_t *floppy, > > > memcpy(rq->cmd, pc->c, 12); > > > > > > pc->rq = rq; > > > - pc->b_count = cmd == READ ? 0 : rq->bio->bi_size; > > > + pc->b_count = 0; > > > if (rq->cmd_flags & REQ_RW) > > > pc->flags |= PC_FLAG_WRITING; > > > pc->buf = NULL; > > > > Don't we also need to zero pc->b_count in idefloppy_blockpc_cmd()? > > > > [ idefloppy_init_pc() clears whole pc so ->b_count assignment > > to zero is not strictly necessary ] > > We probably should and i should've probably hit that during testing and maybe > hit an OOPS along that path but we don't do REQ_TYPE_BLOCK_PC in ide-floppy > yet, as it appears, and since idefloppy_blockpc_cmd() is only called when > blk_pc_request(rq) that's why this one doesn't matter here. We should consider > it though when we convert to using BLOCK_PC type rq's. Unless somebody tries to use SG_IO ioctl (however I don't know if anybody has actually ever tried so it as well may be that it hasn't worked before...). Anyway I applied the patch and fixed pc->b_count while at it (just-in-case). -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
