Re: 2.6.27-rc1 (2fca5c): libata: kernel cant boot

[Jens Axboe <jens.axboe@oracle.com>]

On Sat, Oct 25 2008, Jens Axboe wrote:
> On Sat, Oct 25 2008, Petr Vandrovec wrote:
> > Jens Axboe wrote:
> > >On Fri, Oct 24 2008, Elias Oltmanns wrote:
> > >>Jens Axboe <jens.axboe@oracle.com> wrote:
> > >>>From e598055dde1951c47c8b3522616f6ebff0ed9847 Mon Sep 17 00:00:00 2001
> > >>>From: Jens Axboe <jens.axboe@oracle.com>
> > >>>Date: Fri, 24 Oct 2008 09:22:42 +0200
> > >>>Subject: [PATCH] libata: fix bug with non-ncq devices
> > >>>
> > >>>The recent commit 201f1b98822078c808b5e2d379a6ddbfc0a06ee1 to enable
> > >>Wouldn't that be commit 2fca5ccf97d2c28bcfce44f5b07d85e74e3cd18e?
> > >
> > >Yes that is correct, the other commit is actually a private one in my
> > >tree for other libata changes. Updated patch below, thanks for checking!
> > >
> > >From e598055dde1951c47c8b3522616f6ebff0ed9847 Mon Sep 17 00:00:00 2001
> > >From: Jens Axboe <jens.axboe@oracle.com>
> > >Date: Fri, 24 Oct 2008 09:22:42 +0200
> > >Subject: [PATCH] libata: fix bug with non-ncq devices
> > 
> > Hello,
> >   this fixes my DVD, but unfortunately NCQ devices connected to PMP are 
> > still dead - apparently as soon as mount() tries to do serious I/O on 
> > the drive.  Backing out both post-2.6.28-rc1 fix as well as your 
> > original change brings storage back.  I suspect that problem is that 
> > with PMP same tag cannot be (should not be?  must not be?) used on 
> > multiple devices behind PMP - and before your change tags were allocated 
> > per-port, while now they are allocated per-device.
> 
> That would indeed break, this requires allocating the tag map in the

Totally untested, does this work?

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 4b95c43..0785c46 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1107,6 +1107,10 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
 
 		depth = min(sdev->host->can_queue, ata_id_queue_depth(dev->id));
 		depth = min(ATA_MAX_QUEUE - 1, depth);
+
+		if (dev->link->ap->pmp_link)
+			scsi_init_shared_tag_map(sdev->host, ATA_MAX_QUEUE - 1);
+
 		scsi_set_tag_type(sdev, MSG_SIMPLE_TAG);
 		scsi_activate_tcq(sdev, depth);
 	}

-- 
Jens Axboe