libata: Fix retrieving of active qcs

commit 8385d756e114f2df8568e508902d5f9850817ffb upstream.

ata_qc_complete_multiple() is called with a mask of the still active
tags.

mv_sata doesn't have this information directly and instead calculates
the still active tags from the started tags (ap->qc_active) and the
finished tags as (ap->qc_active ^ done_mask)

Since 28361c40368 the hw_tag and tag are no longer the same and the
equation is no longer valid. In ata_exec_internal_sg() ap->qc_active is
initialized as 1ULL << ATA_TAG_INTERNAL, but in hardware tag 0 is
started and this will be in done_mask on completion. ap->qc_active ^
done_mask becomes 0x100000000 ^ 0x1 = 0x100000001 and thus tag 0 used as
the internal tag will never be reported as completed.

This is fixed by introducing ata_qc_get_active() which returns the
active hardware tags and calling it where appropriate.

This is tested on mv_sata, but sata_fsl and sata_nv suffer from the same
problem. There is another case in sata_nv that most likely needs fixing
as well, but this looks a little different, so I wasn't confident enough
to change that.

Fixes: 28361c403683 ("libata: add extra internal command")
Cc: stable@vger.kernel.org
Tested-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add missing export of ata_qc_get_active(), as per Pali.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c
index 72c9b922a77b..761577d57ff3 100644
--- a/drivers/ata/sata_nv.c
+++ b/drivers/ata/sata_nv.c
@@ -1000,7 +1000,7 @@ static irqreturn_t nv_adma_interrupt(int irq, void *dev_instance)
 					check_commands = 0;
 				check_commands &= ~(1 << pos);
 			}
-			ata_qc_complete_multiple(ap, ap->qc_active ^ done_mask);
+			ata_qc_complete_multiple(ap, ata_qc_get_active(ap) ^ done_mask);
 		}
 	}