linux/drivers/net/usb/plusb.c
Sarah Sharp e1f12eb6ba USB: Disable hub-initiated LPM for comms devices.
Hub-initiated LPM is not good for USB communications devices.  Comms
devices should be able to tell when their link can go into a lower power
state, because they know when an incoming transmission is finished.
Ideally, these devices would slam their links into a lower power state,
using the device-initiated LPM, after finishing the last packet of their
data transfer.

If we enable the idle timeouts for the parent hubs to enable
hub-initiated LPM, we will get a lot of useless LPM packets on the bus
as the devices reject LPM transitions when they're in the middle of
receiving data.  Worse, some devices might blindly accept the
hub-initiated LPM and power down their radios while they're in the
middle of receiving a transmission.

The Intel Windows folks are disabling hub-initiated LPM for all USB
communications devices under a xHCI USB 3.0 host.  In order to keep
the Linux behavior as close as possible to Windows, we need to do the
same in Linux.

Set the disable_hub_initiated_lpm flag for for all USB communications
drivers.  I know there aren't currently any USB 3.0 devices that
implement these class specifications, but we should be ready if they do.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Hansjoerg Lipp <hjlipp@web.de>
Cc: Tilman Schmidt <tilman@imap.cc>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Jan Dumon <j.dumon@option.com>
Cc: Petko Manolov <petkan@users.sourceforge.net>
Cc: Steve Glendinning <steve.glendinning@smsc.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: "Luis R. Rodriguez" <mcgrof@qca.qualcomm.com>
Cc: Jouni Malinen <jouni@qca.qualcomm.com>
Cc: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Cc: Senthil Balasubramanian <senthilb@qca.qualcomm.com>
Cc: Christian Lamparter <chunkeey@googlemail.com>
Cc: Brett Rudley <brudley@broadcom.com>
Cc: Roland Vossen <rvossen@broadcom.com>
Cc: Arend van Spriel <arend@broadcom.com>
Cc: "Franky (Zhenhui) Lin" <frankyl@broadcom.com>
Cc: Kan Yan <kanyan@broadcom.com>
Cc: Dan Williams <dcbw@redhat.com>
Cc: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Cc: Gertjan van Wingerde <gwingerde@gmail.com>
Cc: Helmut Schaa <helmut.schaa@googlemail.com>
Cc: Herton Ronaldo Krzesinski <herton@canonical.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Chaoming Li <chaoming_li@realsil.com.cn>
Cc: Daniel Drake <dsd@gentoo.org>
Cc: Ulrich Kunitz <kune@deine-taler.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
2012-05-18 15:42:55 -07:00

162 lines
5 KiB
C

/*
* PL-2301/2302 USB host-to-host link cables
* Copyright (C) 2000-2005 by David Brownell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
// #define DEBUG // error path messages, extra info
// #define VERBOSE // more; success messages
#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/usb/usbnet.h>
/*
* Prolific PL-2301/PL-2302 driver ... http://www.prolific.com.tw/
*
* The protocol and handshaking used here should be bug-compatible
* with the Linux 2.2 "plusb" driver, by Deti Fliegl.
*
* HEADS UP: this handshaking isn't all that robust. This driver
* gets confused easily if you unplug one end of the cable then
* try to connect it again; you'll need to restart both ends. The
* "naplink" software (used by some PlayStation/2 deveopers) does
* the handshaking much better! Also, sometimes this hardware
* seems to get wedged under load. Prolific docs are weak, and
* don't identify differences between PL2301 and PL2302, much less
* anything to explain the different PL2302 versions observed.
*
* NOTE: pl2501 has several modes, including pl2301 and pl2302
* compatibility. Some docs suggest the difference between 2301
* and 2302 is only to make MS-Windows use a different driver...
*
* pl25a1 glue based on patch from Tony Gibbs. Prolific "docs" on
* this chip are as usual incomplete about what control messages
* are supported.
*/
/*
* Bits 0-4 can be used for software handshaking; they're set from
* one end, cleared from the other, "read" with the interrupt byte.
*/
#define PL_S_EN (1<<7) /* (feature only) suspend enable */
/* reserved bit -- rx ready (6) ? */
#define PL_TX_READY (1<<5) /* (interrupt only) transmit ready */
#define PL_RESET_OUT (1<<4) /* reset output pipe */
#define PL_RESET_IN (1<<3) /* reset input pipe */
#define PL_TX_C (1<<2) /* transmission complete */
#define PL_TX_REQ (1<<1) /* transmission received */
#define PL_PEER_E (1<<0) /* peer exists */
static inline int
pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
{
return usb_control_msg(dev->udev,
usb_rcvctrlpipe(dev->udev, 0),
req,
USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
val, index,
NULL, 0,
USB_CTRL_GET_TIMEOUT);
}
static inline int
pl_clear_QuickLink_features(struct usbnet *dev, int val)
{
return pl_vendor_req(dev, 1, (u8) val, 0);
}
static inline int
pl_set_QuickLink_features(struct usbnet *dev, int val)
{
return pl_vendor_req(dev, 3, (u8) val, 0);
}
static int pl_reset(struct usbnet *dev)
{
int status;
/* some units seem to need this reset, others reject it utterly.
* FIXME be more like "naplink" or windows drivers.
*/
status = pl_set_QuickLink_features(dev,
PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
if (status != 0 && netif_msg_probe(dev))
netif_dbg(dev, link, dev->net, "pl_reset --> %d\n", status);
return 0;
}
static const struct driver_info prolific_info = {
.description = "Prolific PL-2301/PL-2302/PL-25A1",
.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT,
/* some PL-2302 versions seem to fail usb_set_interface() */
.reset = pl_reset,
};
/*-------------------------------------------------------------------------*/
/*
* Proilific's name won't normally be on the cables, and
* may not be on the device.
*/
static const struct usb_device_id products [] = {
/* full speed cables */
{
USB_DEVICE(0x067b, 0x0000), // PL-2301
.driver_info = (unsigned long) &prolific_info,
}, {
USB_DEVICE(0x067b, 0x0001), // PL-2302
.driver_info = (unsigned long) &prolific_info,
},
/* high speed cables */
{
USB_DEVICE(0x067b, 0x25a1), /* PL-25A1, no eeprom */
.driver_info = (unsigned long) &prolific_info,
}, {
USB_DEVICE(0x050d, 0x258a), /* Belkin F5U258/F5U279 (PL-25A1) */
.driver_info = (unsigned long) &prolific_info,
},
{ }, // END
};
MODULE_DEVICE_TABLE(usb, products);
static struct usb_driver plusb_driver = {
.name = "plusb",
.id_table = products,
.probe = usbnet_probe,
.disconnect = usbnet_disconnect,
.suspend = usbnet_suspend,
.resume = usbnet_resume,
.disable_hub_initiated_lpm = 1,
};
module_usb_driver(plusb_driver);
MODULE_AUTHOR("David Brownell");
MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1 USB Host to Host Link Driver");
MODULE_LICENSE("GPL");