In order to do away with queueing read requests on the pipeline, several things
have to be done:
1. Do not allocate additional pipeline stages in idetape_init_read() until
(tape->nr_stages < max_stages) and do only read operation preparations. As a
collateral result, idetape_add_stage_tail() becomes unused so remove it.
2. Queue the read request's buffer directly thru idetape_queue_rw_tail().
3. Remove now unused idetape_kmalloc_stage() and idetape_switch_buffers().
[bart: simplify the original patch]
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
5e69bd959d