From e013e13bf605b9e6b702adffbe2853cfc60e7806 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 24 Oct 2008 09:22:42 +0200 Subject: [PATCH] libata: fix bug with non-ncq devices The recent commit 2fca5ccf97d2c28bcfce44f5b07d85e74e3cd18e ("libata: switch to using block layer tagging support") 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 Reported-by: Alexander Beregalov Tested-by: Paul Mundt Tested-by: Dave Young Tested-by: Rafael J. Wysocki Signed-off-by: Linus Torvalds --- drivers/ata/libata-scsi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index d5b9b7266c8..4b95c4387e9 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; -- 2.41.0