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Commit 624d6c07 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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USB: remove excess code from hub.c 

This patch (as917) removes a now-unnecessary level of subroutine
nesting from hub.c.  Since usb_port_suspend() does nothing but call
hub_port_suspend(), and usb_port_resume() does nothing but call
hub_port_resume(), there's no reason to keep the routines separate.

Also included in the patch are a few cosmetic changes involving
whitespace and use of braces.
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 686314cf
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Inline Side-by-side
Showing with 71 additions and 104 deletions
drivers/usb/core/hub.c
View file @ 624d6c07
......@@ -1625,6 +1625,19 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
#ifdef CONFIG_USB_SUSPEND
/*
* usb_port_suspend - suspend a usb device's upstream port
* @udev: device that's no longer in active use, not a root hub
* Context: must be able to sleep; device not locked; pm locks held
*
* Suspends a USB device that isn't in active use, conserving power.
* Devices may wake out of a suspend, if anything important happens,
* using the remote wakeup mechanism. They may also be taken out of
* suspend by the host, using usb_port_resume(). It's also routine
* to disconnect devices while they are suspended.
*
* This only affects the USB hardware for a device; its interfaces
* (and, for hubs, child devices) must already have been suspended.
*
* Selective port suspend reduces power; most suspended devices draw
* less than 500 uA. It's also used in OTG, along with remote wakeup.
* All devices below the suspended port are also suspended.
......@@ -1633,10 +1646,34 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
* also support "remote wakeup", where the device can activate the USB
* tree above them to deliver data, such as a keypress or packet. In
* some cases, this wakes the USB host.
*
* Suspending OTG devices may trigger HNP, if that's been enabled
* between a pair of dual-role devices. That will change roles, such
* as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
*
* Devices on USB hub ports have only one "suspend" state, corresponding
* to ACPI D2, "may cause the device to lose some context".
* State transitions include:
*
* - suspend, resume ... when the VBUS power link stays live
* - suspend, disconnect ... VBUS lost
*
* Once VBUS drop breaks the circuit, the port it's using has to go through
* normal re-enumeration procedures, starting with enabling VBUS power.
* Other than re-initializing the hub (plug/unplug, except for root hubs),
* Linux (2.6) currently has NO mechanisms to initiate that: no khubd
* timer, no SRP, no requests through sysfs.
*
* If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
* the root hub for their bus goes into global suspend ... so we don't
* (falsely) update the device power state to say it suspended.
*
* Returns 0 on success, else negative errno.
*/
static int hub_port_suspend(struct usb_hub *hub, int port1,
struct usb_device *udev)
int usb_port_suspend(struct usb_device *udev)
{
struct usb_hub *hub = hdev_to_hub(udev->parent);
int port1 = udev->portnum;
int status;
// dev_dbg(hub->intfdev, "suspend port %d\n", port1);
......@@ -1654,16 +1691,14 @@ static int hub_port_suspend(struct usb_hub *hub, int port1,
NULL, 0,
USB_CTRL_SET_TIMEOUT);
if (status)
dev_dbg(&udev->dev,
"won't remote wakeup, status %d\n",
dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
status);
}
/* see 7.1.7.6 */
status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
if (status) {
dev_dbg(hub->intfdev,
"can't suspend port %d, status %d\n",
dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
port1, status);
/* paranoia: "should not happen" */
(void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
......@@ -1681,52 +1716,6 @@ static int hub_port_suspend(struct usb_hub *hub, int port1,
return status;
}
/*
* usb_port_suspend - suspend a usb device's upstream port
* @udev: device that's no longer in active use
* Context: must be able to sleep; device not locked; pm locks held
*
* Suspends a USB device that isn't in active use, conserving power.
* Devices may wake out of a suspend, if anything important happens,
* using the remote wakeup mechanism. They may also be taken out of
* suspend by the host, using usb_port_resume(). It's also routine
* to disconnect devices while they are suspended.
*
* This only affects the USB hardware for a device; its interfaces
* (and, for hubs, child devices) must already have been suspended.
*
* Suspending OTG devices may trigger HNP, if that's been enabled
* between a pair of dual-role devices. That will change roles, such
* as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
*
* Devices on USB hub ports have only one "suspend" state, corresponding
* to ACPI D2, "may cause the device to lose some context".
* State transitions include:
*
* - suspend, resume ... when the VBUS power link stays live
* - suspend, disconnect ... VBUS lost
*
* Once VBUS drop breaks the circuit, the port it's using has to go through
* normal re-enumeration procedures, starting with enabling VBUS power.
* Other than re-initializing the hub (plug/unplug, except for root hubs),
* Linux (2.6) currently has NO mechanisms to initiate that: no khubd
* timer, no SRP, no requests through sysfs.
*
* If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
* the root hub for their bus goes into global suspend ... so we don't
* (falsely) update the device power state to say it suspended.
*
* Returns 0 on success, else negative errno.
*/
int usb_port_suspend(struct usb_device *udev)
{
int status = 0;
status = hub_port_suspend(hdev_to_hub(udev->parent),
udev->portnum, udev);
return status;
}
/*
* If the USB "suspend" state is in use (rather than "global suspend"),
* many devices will be individually taken out of suspend state using
......@@ -1760,11 +1749,10 @@ static int finish_port_resume(struct usb_device *udev)
if (status >= 0)
status = (status == 2 ? 0 : -ENODEV);
if (status)
dev_dbg(&udev->dev,
"gone after usb resume? status %d\n",
if (status) {
dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
status);
else if (udev->actconfig) {
} else if (udev->actconfig) {
le16_to_cpus(&devstatus);
if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
status = usb_control_msg(udev,
......@@ -1783,9 +1771,23 @@ static int finish_port_resume(struct usb_device *udev)
return status;
}
static int
hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
/*
* usb_port_resume - re-activate a suspended usb device's upstream port
* @udev: device to re-activate, not a root hub
* Context: must be able to sleep; device not locked; pm locks held
*
* This will re-activate the suspended device, increasing power usage
* while letting drivers communicate again with its endpoints.
* USB resume explicitly guarantees that the power session between
* the host and the device is the same as it was when the device
* suspended.
*
* Returns 0 on success, else negative errno.
*/
int usb_port_resume(struct usb_device *udev)
{
struct usb_hub *hub = hdev_to_hub(udev->parent);
int port1 = udev->portnum;
int status;
u16 portchange, portstatus;
......@@ -1802,8 +1804,7 @@ hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
status = clear_port_feature(hub->hdev,
port1, USB_PORT_FEAT_SUSPEND);
if (status) {
dev_dbg(hub->intfdev,
"can't resume port %d, status %d\n",
dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
port1, status);
} else {
/* drive resume for at least 20 msec */
......@@ -1839,8 +1840,10 @@ hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
status = finish_port_resume(udev);
}
}
if (status < 0)
if (status < 0) {
dev_dbg(&udev->dev, "can't resume, status %d\n", status);
hub_port_logical_disconnect(hub, port1);
}
clear_bit(port1, hub->busy_bits);
if (!hub->hdev->parent && !hub->busy_bits[0])
......@@ -1849,30 +1852,6 @@ hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
return status;
}
/*
* usb_port_resume - re-activate a suspended usb device's upstream port
* @udev: device to re-activate
* Context: must be able to sleep; device not locked; pm locks held
*
* This will re-activate the suspended device, increasing power usage
* while letting drivers communicate again with its endpoints.
* USB resume explicitly guarantees that the power session between
* the host and the device is the same as it was when the device
* suspended.
*
* Returns 0 on success, else negative errno.
*/
int usb_port_resume(struct usb_device *udev)
{
int status;
status = hub_port_resume(hdev_to_hub(udev->parent),
udev->portnum, udev);
if (status < 0)
dev_dbg(&udev->dev, "can't resume, status %d\n", status);
return status;
}
static int remote_wakeup(struct usb_device *udev)
{
int status = 0;
......@@ -1896,18 +1875,6 @@ int usb_port_suspend(struct usb_device *udev)
return 0;
}
static inline int
finish_port_resume(struct usb_device *udev)
{
return 0;
}
static inline int
hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
{
return 0;
}
int usb_port_resume(struct usb_device *udev)
{
return 0;
......
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