source: mainline/uspace/drv/bus/usb/uhci/transfer_list.h@ 629255a

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 629255a was 4db49344, checked in by Ondřej Hlavatý <aearsis@…>, 8 years ago

usb: fix wrong design of transfer aborting

Apparently, we didn't do a good job in thinking through the problem.
In older HCs, it was done just wrong - the UHCI implementation commited
a batch that could have been already aborted, and EHCI+OHCI might miss
an interrupt because they commited the batch sooner than they added it
to their checked list.

This commit takes everything from the other end, which is probably the
only right one. Instead of an endpoint having an extra mutex, it
inherits a mutex from the outside. It never locks it though, it just
checks if the mutex is locked and uses it for waiting on condition
variables.

This mutex is supposed to be the one which the HC driver uses for
locking its structures in scheduling. This way, we avoid the ABBA
deadlock completely, while preserving the synchronization on an
endpoint.

The good thing is that this implementation is much easier to extend with
multiple active batches per endpoint.
  • Property mode set to 100644
File size: 2.5 KB
Line 
1/*
2 * Copyright (c) 2011 Jan Vesely
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup drvusbuhcihc
30 * @{
31 */
32/** @file
33 * @brief UHCI driver transfer list structure
34 */
35
36#ifndef DRV_UHCI_TRANSFER_LIST_H
37#define DRV_UHCI_TRANSFER_LIST_H
38
39#include <adt/list.h>
40#include <fibril_synch.h>
41
42#include "hw_struct/queue_head.h"
43#include "uhci_batch.h"
44/** Structure maintaining both hw queue and software list
45 * of currently executed transfers
46 */
47typedef struct transfer_list {
48 /** Guard against multiple add/remove races */
49 fibril_mutex_t guard;
50 /** UHCI hw structure representing this queue */
51 qh_t *queue_head;
52 /** Assigned name, for nicer debug output */
53 const char *name;
54 /** List of all batches in this list */
55 list_t batch_list;
56} transfer_list_t;
57
58void transfer_list_fini(transfer_list_t *);
59int transfer_list_init(transfer_list_t *, const char *);
60void transfer_list_set_next(transfer_list_t *, transfer_list_t *);
61int transfer_list_add_batch(transfer_list_t *, uhci_transfer_batch_t *);
62void transfer_list_remove_batch(transfer_list_t *, uhci_transfer_batch_t *);
63void transfer_list_check_finished(transfer_list_t *);
64void transfer_list_abort_all(transfer_list_t *);
65
66#endif
67
68/**
69 * @}
70 */
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