On Fri, Oct 24 2008, Paul Mundt wrote: > On Fri, Oct 24, 2008 at 09:13:29AM +0200, Jens Axboe wrote: > > On Fri, Oct 24 2008, Jens Axboe wrote: > > > On Fri, Oct 24 2008, Alexander Beregalov wrote: > > > > Hi > > > > > > > > commit 2fca5ccf97d2c28bcfce44f5b07d85e74e3cd18e > > > > Author: Jens Axboe <jens.axboe@xxxxxxxxxx> > > > > Date: Wed Oct 22 09:34:49 2008 +0200 > > > > > > > > libata: switch to using block layer tagging support > > > > > > > > > > > > This kernel can not read even 0 sector on disk with rootfs. It > > > > initialized disk, but cant read it at all. > > > > CMD646 on Sparc > > > > > > > > Rverting helped. > > > > > > Doh, how annoying! What driver does that controller use? PATA doesn't > > > even use NCQ, so it's a bit of an oddity that it makes a difference at > > > all. > > > > > > Can you provide the boot messages? > > > > Darn, this smells like a train wreck. I'm assuming this fixes it? > > > Yes, that fixes it. OK, that's pretty bad. 2.6.28-rc1 will not work on any box using libata with non-ncq disks. If you need me, I'll be at the bar. ---------- >From e598055dde1951c47c8b3522616f6ebff0ed9847 Mon Sep 17 00:00:00 2001 From: Jens Axboe <jens.axboe@xxxxxxxxxx> Date: Fri, 24 Oct 2008 09:22:42 +0200 Subject: [PATCH] libata: fix bug with non-ncq devices The recent commit 201f1b98822078c808b5e2d379a6ddbfc0a06ee1 to enable support for block layer tagging in libata was broken for non-NCQ devices. The block layer initializes the tag field to -1 to detect invalid uses of a tag, and if the libata devices does NOT support NCQ, we just used that field to index the internal command list. So we need to check for -1 first and only use the tag field if it's valid. Signed-off-by: Jens Axboe <jens.axboe@xxxxxxxxxx> --- drivers/ata/libata-scsi.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index d5b9b72..4b95c43 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -708,7 +708,11 @@ static struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev, { struct ata_queued_cmd *qc; - qc = ata_qc_new_init(dev, cmd->request->tag); + if (cmd->request->tag != -1) + qc = ata_qc_new_init(dev, cmd->request->tag); + else + qc = ata_qc_new_init(dev, 0); + if (qc) { qc->scsicmd = cmd; qc->scsidone = done; -- 1.6.0.2.588.g3102 -- Jens Axboe -- 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