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wusb: reset WUSB devices with SetAddress(0)
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Using a Reset Device IE to reset a WUSB device is too heavyweight as it
causes the devcie to disconnect (which the USB stack does not expect and
cannot handle).  Instead, do a SetAddress(0); SetAddress(AuthAddr) for
authenticated devices.

Unauthenticated devices will not be reset and the stack will have to rely
on the device timing out after TrustTimeout and disconnecting.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
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David Vrabel committed Oct 28, 2008
1 parent 1cde7f6 commit 4656d5d
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Showing 4 changed files with 25 additions and 122 deletions.
100 changes: 1 addition & 99 deletions drivers/usb/wusbcore/devconnect.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -57,9 +57,6 @@
* Called by notif.c:wusb_handle_dn_connect()
* when a DN_Connect is received.
*
* wusbhc_devconnect_auth() Called by rh.c:wusbhc_rh_port_reset() when
* doing the device connect sequence.
*
* wusb_devconnect_acked() Ack done, release resources.
*
* wusb_handle_dn_alive() Called by notif.c:wusb_handle_dn()
Expand All @@ -69,9 +66,6 @@
* process a disconenct request from a
* device.
*
* wusb_dev_reset() Called by rh.c:wusbhc_rh_port_reset() when
* resetting a device.
*
* __wusb_dev_disable() Called by rh.c:wusbhc_rh_clear_port_feat() when
* disabling a port.
*
Expand Down Expand Up @@ -366,12 +360,10 @@ void wusbhc_devconnect_ack(struct wusbhc *wusbhc, struct wusb_dn_connect *dnc,
port->wusb_dev = wusb_dev;
port->status |= USB_PORT_STAT_CONNECTION;
port->change |= USB_PORT_STAT_C_CONNECTION;
port->reset_count = 0;
/* Now the port status changed to connected; khubd will
* pick the change up and try to reset the port to bring it to
* the enabled state--so this process returns up to the stack
* and it calls back into wusbhc_rh_port_reset() who will call
* devconnect_auth().
* and it calls back into wusbhc_rh_port_reset().
*/
error_unlock:
mutex_unlock(&wusbhc->mutex);
Expand Down Expand Up @@ -413,9 +405,6 @@ static void __wusbhc_dev_disconnect(struct wusbhc *wusbhc,
wusb_dev_put(wusb_dev);
}
port->wusb_dev = NULL;
/* don't reset the reset_count to zero or wusbhc_rh_port_reset will get
* confused! We only reset to zero when we connect a new device.
*/

/* After a device disconnects, change the GTK (see [WUSB]
* section 6.2.11.2). */
Expand All @@ -428,39 +417,6 @@ static void __wusbhc_dev_disconnect(struct wusbhc *wusbhc,
*/
}

/*
* Authenticate a device into the WUSB Cluster
*
* Called from the Root Hub code (rh.c:wusbhc_rh_port_reset()) when
* asking for a reset on a port that is not enabled (ie: first connect
* on the port).
*
* Performs the 4way handshake to allow the device to comunicate w/ the
* WUSB Cluster securely; once done, issue a request to the device for
* it to change to address 0.
*
* This mimics the reset step of Wired USB that once resetting a
* device, leaves the port in enabled state and the dev with the
* default address (0).
*
* WUSB1.0[7.1.2]
*
* @port_idx: port where the change happened--This is the index into
* the wusbhc port array, not the USB port number.
*/
int wusbhc_devconnect_auth(struct wusbhc *wusbhc, u8 port_idx)
{
struct device *dev = wusbhc->dev;
struct wusb_port *port = wusb_port_by_idx(wusbhc, port_idx);

d_fnstart(3, dev, "(%p, %u)\n", wusbhc, port_idx);
port->status &= ~USB_PORT_STAT_RESET;
port->status |= USB_PORT_STAT_ENABLE;
port->change |= USB_PORT_STAT_C_RESET | USB_PORT_STAT_C_ENABLE;
d_fnend(3, dev, "(%p, %u) = 0\n", wusbhc, port_idx);
return 0;
}

/*
* Refresh the list of keep alives to emit in the MMC
*
Expand Down Expand Up @@ -661,60 +617,6 @@ static void wusbhc_handle_dn_disconnect(struct wusbhc *wusbhc, struct wusb_dev *
mutex_unlock(&wusbhc->mutex);
}

/*
* Reset a WUSB device on a HWA
*
* @wusbhc
* @port_idx Index of the port where the device is
*
* In Wireless USB, a reset is more or less equivalent to a full
* disconnect; so we just do a full disconnect and send the device a
* Device Reset IE (WUSB1.0[7.5.11]) giving it a few millisecs (6 MMCs).
*
* @wusbhc should be refcounted and unlocked
*/
int wusbhc_dev_reset(struct wusbhc *wusbhc, u8 port_idx)
{
int result;
struct device *dev = wusbhc->dev;
struct wusb_dev *wusb_dev;
struct wuie_reset *ie;

d_fnstart(3, dev, "(%p, %u)\n", wusbhc, port_idx);
mutex_lock(&wusbhc->mutex);
result = 0;
wusb_dev = wusb_port_by_idx(wusbhc, port_idx)->wusb_dev;
if (wusb_dev == NULL) {
/* reset no device? ignore */
dev_dbg(dev, "RESET: no device at port %u, ignoring\n",
port_idx);
goto error_unlock;
}
result = -ENOMEM;
ie = kzalloc(sizeof(*ie), GFP_KERNEL);
if (ie == NULL)
goto error_unlock;
ie->hdr.bLength = sizeof(ie->hdr) + sizeof(ie->CDID);
ie->hdr.bIEIdentifier = WUIE_ID_RESET_DEVICE;
ie->CDID = wusb_dev->cdid;
result = wusbhc_mmcie_set(wusbhc, 0xff, 6, &ie->hdr);
if (result < 0) {
dev_err(dev, "RESET: cant's set MMC: %d\n", result);
goto error_kfree;
}
__wusbhc_dev_disconnect(wusbhc, wusb_port_by_idx(wusbhc, port_idx));

/* 120ms, hopefully 6 MMCs (FIXME) */
msleep(120);
wusbhc_mmcie_rm(wusbhc, &ie->hdr);
error_kfree:
kfree(ie);
error_unlock:
mutex_unlock(&wusbhc->mutex);
d_fnend(3, dev, "(%p, %u) = %d\n", wusbhc, port_idx, result);
return result;
}

/*
* Handle a Device Notification coming a host
*
Expand Down
40 changes: 22 additions & 18 deletions drivers/usb/wusbcore/rh.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -77,13 +77,17 @@
/*
* Reset a fake port
*
* This can be called to reset a port from any other state or to reset
* it when connecting. In Wireless USB they are different; when doing
* a new connect that involves going over the authentication. When
* just reseting, its a different story.
* Using a Reset Device IE is too heavyweight as it causes the device
* to enter the UnConnected state and leave the cluster, this can mean
* that when the device reconnects it is connected to a different fake
* port.
*
* The Linux USB stack resets a port twice before it considers it
* enabled, so we have to detect and ignore that.
* Instead, reset authenticated devices with a SetAddress(0), followed
* by a SetAddresss(AuthAddr).
*
* For unauthenticated devices just pretend to reset but do nothing.
* If the device initialization continues to fail it will eventually
* time out after TrustTimeout and enter the UnConnected state.
*
* @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
*
Expand All @@ -97,20 +101,20 @@ static int wusbhc_rh_port_reset(struct wusbhc *wusbhc, u8 port_idx)
{
int result = 0;
struct wusb_port *port = wusb_port_by_idx(wusbhc, port_idx);
struct wusb_dev *wusb_dev = port->wusb_dev;

port->status |= USB_PORT_STAT_RESET;
port->change |= USB_PORT_STAT_C_RESET;

d_fnstart(3, wusbhc->dev, "(wusbhc %p port_idx %u)\n",
wusbhc, port_idx);
if (port->reset_count == 0) {
wusbhc_devconnect_auth(wusbhc, port_idx);
port->reset_count++;
} else if (port->reset_count == 1)
/* see header */
d_printf(2, wusbhc->dev, "Ignoring second reset on port_idx "
"%u\n", port_idx);
if (wusb_dev->addr & WUSB_DEV_ADDR_UNAUTH)
result = 0;
else
result = wusbhc_dev_reset(wusbhc, port_idx);
d_fnend(3, wusbhc->dev, "(wusbhc %p port_idx %u) = %d\n",
wusbhc, port_idx, result);
result = wusb_dev_update_address(wusbhc, wusb_dev);

port->status &= ~USB_PORT_STAT_RESET;
port->status |= USB_PORT_STAT_ENABLE;
port->change |= USB_PORT_STAT_C_RESET | USB_PORT_STAT_C_ENABLE;

return result;
}

Expand Down
3 changes: 1 addition & 2 deletions drivers/usb/wusbcore/security.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -338,8 +338,7 @@ static void hs_printk(unsigned level, struct device *dev,
* Before the device's address (as known by it) was usb_dev->devnum |
* 0x80 (unauthenticated address). With this we update it to usb_dev->devnum.
*/
static int wusb_dev_update_address(struct wusbhc *wusbhc,
struct wusb_dev *wusb_dev)
int wusb_dev_update_address(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
{
int result = -ENOMEM;
struct usb_device *usb_dev = wusb_dev->usb_dev;
Expand Down
4 changes: 1 addition & 3 deletions drivers/usb/wusbcore/wusbhc.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -154,7 +154,6 @@ struct wusb_port {
u16 status;
u16 change;
struct wusb_dev *wusb_dev; /* connected device's info */
unsigned reset_count;
u32 ptk_tkid;
};

Expand Down Expand Up @@ -387,10 +386,8 @@ extern void wusbhc_devconnect_destroy(struct wusbhc *);
extern int wusbhc_devconnect_start(struct wusbhc *wusbhc,
const struct wusb_ckhdid *chid);
extern void wusbhc_devconnect_stop(struct wusbhc *wusbhc);
extern int wusbhc_devconnect_auth(struct wusbhc *, u8);
extern void wusbhc_handle_dn(struct wusbhc *, u8 srcaddr,
struct wusb_dn_hdr *dn_hdr, size_t size);
extern int wusbhc_dev_reset(struct wusbhc *wusbhc, u8 port);
extern void __wusbhc_dev_disable(struct wusbhc *wusbhc, u8 port);
extern int wusb_usb_ncb(struct notifier_block *nb, unsigned long val,
void *priv);
Expand Down Expand Up @@ -436,6 +433,7 @@ extern void wusb_dev_sec_rm(struct wusb_dev *) ;
extern int wusb_dev_4way_handshake(struct wusbhc *, struct wusb_dev *,
struct wusb_ckhdid *ck);
void wusbhc_gtk_rekey(struct wusbhc *wusbhc);
int wusb_dev_update_address(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev);


/* WUSB Cluster ID handling */
Expand Down

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