Re: [PATCH 04/40] ide-scsi: fix Interrupt Reason checking in idescsi_pc_intr()

From: Bartlomiej Zolnierkiewicz
Date: Mon May 26 2008 - 15:23:53 EST


On Monday 19 May 2008, Borislav Petkov wrote:
> On Sun, May 18, 2008 at 08:55:03PM +0200, Bartlomiej Zolnierkiewicz wrote:
> > Set PC_FLAG_WRITING pc flag in idescsi_queue() (if needed)
> > and then fix Interrupt Reason checking in idescsi_pc_intr().
> >
> > Cc: Borislav Petkov <petkovbb@xxxxxxxxx>
> > Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>
> > ---
> > drivers/scsi/ide-scsi.c | 17 +++++++++++------
> > 1 file changed, 11 insertions(+), 6 deletions(-)
> >
> > Index: b/drivers/scsi/ide-scsi.c
> > ===================================================================
> > --- a/drivers/scsi/ide-scsi.c
> > +++ b/drivers/scsi/ide-scsi.c
> > @@ -427,7 +427,15 @@ static ide_startstop_t idescsi_pc_intr (
> > printk(KERN_ERR "ide-scsi: CoD != 0 in idescsi_pc_intr\n");
> > return ide_do_reset (drive);
> > }
> > - if (ireason & IO) {
> > + if (((ireason & IO) == IO) == !!(pc->flags & PC_FLAG_WRITING)) {
> > + /* Hopefully, we will never get here */
> > + printk(KERN_ERR "%s: We wanted to %s, but the device wants us "
> > + "to %s!\n", drive->name,
> > + (ireason & IO) ? "Write" : "Read",
> > + (ireason & IO) ? "Read" : "Write");
> > + return ide_do_reset(drive);
> > + }
> > + if (!(pc->flags & PC_FLAG_WRITING)) {
> > temp = pc->xferred + bcount;
> > if (temp > pc->req_xfer) {
> > if (temp > pc->buf_size) {
> > @@ -436,7 +444,6 @@ static ide_startstop_t idescsi_pc_intr (
> > "- discarding data\n");
> > temp = pc->buf_size - pc->xferred;
> > if (temp) {
> > - pc->flags &= ~PC_FLAG_WRITING;
> > if (pc->sg)
> > idescsi_input_buffers(drive, pc,
> > temp);
> > @@ -457,15 +464,11 @@ static ide_startstop_t idescsi_pc_intr (
> > printk (KERN_NOTICE "ide-scsi: The scsi wants to send us more data than expected - allowing transfer\n");
> > #endif /* IDESCSI_DEBUG_LOG */
> > }
> > - }
> > - if (ireason & IO) {
> > - pc->flags &= ~PC_FLAG_WRITING;
> > if (pc->sg)
> > idescsi_input_buffers(drive, pc, bcount);
> > else
> > hwif->input_data(drive, NULL, pc->cur_pos, bcount);
> > } else {
> > - pc->flags |= PC_FLAG_WRITING;
>
> Yeah, what was the driver doing turning on/off that flag in the irq handler? Are
> those pc's getting reused in ide-scsi... I guess this is one of the bugs you
> were talking about :).

I guess that it was a left-over from the old days...

[ nowadays idescsi_queue() dynamically allocates new pc-s ]

Thanks,
Bart
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