• Sascha Hauer's avatar
    libata: Fix retrieving of active qcs · 8385d756
    Sascha Hauer authored
    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 28361c40 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    equation is no longer valid.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: 28361c40 ("libata: add extra internal command")
    Cc: stable@vger.kernel.org
    Tested-by: default avatarPali Rohár <pali.rohar@gmail.com>
    Signed-off-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
    
    Add missing export of ata_qc_get_active(), as per Pali.
    Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
    8385d756
sata_mv.c 122 KB