Use qc->result_tf for temp taskfile storage. Signed-off-by: Albert Lee <albertcc@xxxxxxxxxx> --- Hopefully this can both preserve command TF and doesn't increase kernel stack usage. Patch against the upstream branch of libata-dev. --- upstream0/drivers/scsi/libata-core.c 2006-05-16 11:08:49.000000000 +0800 +++ upstream3/drivers/scsi/libata-core.c 2006-05-18 17:42:49.000000000 +0800 @@ -3862,10 +3862,16 @@ static void atapi_pio_bytes(struct ata_q 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 */ - : 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
