diff options
| -rw-r--r-- | drivers/scsi/libata-core.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index aa38ed3e59a8..bf00d2b2e404 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -3865,10 +3865,16 @@ static void atapi_pio_bytes(struct ata_queued_cmd *qc) unsigned int ireason, bc_lo, bc_hi, bytes; int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0; - ap->ops->tf_read(ap, &qc->tf); - ireason = qc->tf.nsect; - bc_lo = qc->tf.lbam; - bc_hi = qc->tf.lbah; + /* Abuse qc->result_tf for temp storage of intermediate TF + * here to save some kernel stack usage. + * For normal completion, qc->result_tf is not relevant. For + * error, qc->result_tf is later overwritten by ata_qc_complete(). + * So, the correctness of qc->result_tf is not affected. + */ + ap->ops->tf_read(ap, &qc->result_tf); + ireason = qc->result_tf.nsect; + bc_lo = qc->result_tf.lbam; + bc_hi = qc->result_tf.lbah; bytes = (bc_hi << 8) | bc_lo; /* shall be cleared to zero, indicating xfer of data */ |