diff options
Diffstat (limited to 'drivers/usb/core')
| -rw-r--r-- | drivers/usb/core/Kconfig | 25 | ||||
| -rw-r--r-- | drivers/usb/core/hub.c | 27 | ||||
| -rw-r--r-- | drivers/usb/core/quirks.c | 12 | ||||
| -rw-r--r-- | drivers/usb/core/sysfs.c | 22 |
4 files changed, 32 insertions, 54 deletions
diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig index a2b0aa48b8ea..c15621d64579 100644 --- a/drivers/usb/core/Kconfig +++ b/drivers/usb/core/Kconfig @@ -102,31 +102,6 @@ config USB_SUSPEND If you are unsure about this, say N here. -config USB_PERSIST - bool "USB device persistence during system suspend (DANGEROUS)" - depends on USB && PM && EXPERIMENTAL - default n - help - - If you say Y here and enable the "power/persist" attribute - for a USB device, the device's data structures will remain - persistent across system suspend, even if the USB bus loses - power. (This includes hibernation, also known as swsusp or - suspend-to-disk.) The devices will reappear as if by magic - when the system wakes up, with no need to unmount USB - filesystems, rmmod host-controller drivers, or do anything - else. - - WARNING: This option can be dangerous! - - If a USB device is replaced by another of the same type while - the system is asleep, there's a good chance the kernel won't - detect the change. Likewise if the media in a USB storage - device is replaced. When this happens it's almost certain to - cause data corruption and maybe even crash your system. - - If you are unsure, say N here. - config USB_OTG bool depends on USB && EXPERIMENTAL diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index df68e2562582..6dc589955d75 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -30,12 +30,6 @@ #include "hcd.h" #include "hub.h" -#ifdef CONFIG_USB_PERSIST -#define USB_PERSIST 1 -#else -#define USB_PERSIST 0 -#endif - /* if we are in debug mode, always announce new devices */ #ifdef DEBUG #ifndef CONFIG_USB_ANNOUNCE_NEW_DEVICES @@ -695,7 +689,7 @@ static void hub_restart(struct usb_hub *hub, int type) * turn off the various status changes to prevent * khubd from disconnecting it later. */ - if (USB_PERSIST && udev->persist_enabled && status == 0 && + if (udev->persist_enabled && status == 0 && !(portstatus & USB_PORT_STAT_ENABLE)) { if (portchange & USB_PORT_STAT_C_ENABLE) clear_port_feature(hub->hdev, port1, @@ -1923,9 +1917,8 @@ static int finish_port_resume(struct usb_device *udev) * the host and the device is the same as it was when the device * suspended. * - * If CONFIG_USB_PERSIST and @udev->reset_resume are both set then this - * routine won't check that the port is still enabled. Furthermore, - * if @udev->reset_resume is set then finish_port_resume() above will + * If @udev->reset_resume is set then this routine won't check that the + * port is still enabled. Furthermore, finish_port_resume() above will * reset @udev. The end result is that a broken power session can be * recovered and @udev will appear to persist across a loss of VBUS power. * @@ -1937,8 +1930,8 @@ static int finish_port_resume(struct usb_device *udev) * to it will be lost. Using the USB_PERSIST facility, the device can be * made to appear as if it had not disconnected. * - * This facility is inherently dangerous. Although usb_reset_device() - * makes every effort to insure that the same device is present after the + * This facility can be dangerous. Although usb_reset_device() makes + * every effort to insure that the same device is present after the * reset as before, it cannot provide a 100% guarantee. Furthermore it's * quite possible for a device to remain unaltered but its media to be * changed. If the user replaces a flash memory card while the system is @@ -1983,7 +1976,7 @@ int usb_port_resume(struct usb_device *udev) status = hub_port_status(hub, port1, &portstatus, &portchange); SuspendCleared: - if (USB_PERSIST && udev->reset_resume) + if (udev->reset_resume) want_flags = USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION; else @@ -2113,10 +2106,10 @@ static int hub_reset_resume(struct usb_interface *intf) * * The USB host controller driver calls this function when its root hub * is resumed and Vbus power has been interrupted or the controller - * has been reset. The routine marks @rhdev as having lost power. When - * the hub driver is resumed it will take notice; if CONFIG_USB_PERSIST - * is enabled then it will carry out power-session recovery, otherwise - * it will disconnect all the child devices. + * has been reset. The routine marks @rhdev as having lost power. + * When the hub driver is resumed it will take notice and carry out + * power-session recovery for all the "USB-PERSIST"-enabled child devices; + * the others will be disconnected. */ void usb_root_hub_lost_power(struct usb_device *rhdev) { diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c index dfc5418ea10c..f384edf35b44 100644 --- a/drivers/usb/core/quirks.c +++ b/drivers/usb/core/quirks.c @@ -97,4 +97,16 @@ void usb_detect_quirks(struct usb_device *udev) if (udev->descriptor.bDeviceClass != USB_CLASS_HUB) udev->autosuspend_disabled = 1; #endif + +#ifdef CONFIG_PM + /* Hubs are automatically enabled for USB-PERSIST */ + if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) + udev->persist_enabled = 1; +#else + /* In the absense of PM, we can safely enable USB-PERSIST + * for all devices. It will affect things like hub resets + * and EMF-related port disables. + */ + udev->persist_enabled = 1; +#endif /* CONFIG_PM */ } diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index a37ccbd1e007..5b20a60de8ba 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -180,11 +180,9 @@ show_urbnum(struct device *dev, struct device_attribute *attr, char *buf) static DEVICE_ATTR(urbnum, S_IRUGO, show_urbnum, NULL); -#if defined(CONFIG_USB_PERSIST) || defined(CONFIG_USB_SUSPEND) -static const char power_group[] = "power"; -#endif +#ifdef CONFIG_PM -#ifdef CONFIG_USB_PERSIST +static const char power_group[] = "power"; static ssize_t show_persist(struct device *dev, struct device_attribute *attr, char *buf) @@ -222,12 +220,13 @@ static int add_persist_attributes(struct device *dev) if (is_usb_device(dev)) { struct usb_device *udev = to_usb_device(dev); - /* Hubs are automatically enabled for USB_PERSIST */ - if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) - udev->persist_enabled = 1; - rc = sysfs_add_file_to_group(&dev->kobj, - &dev_attr_persist.attr, - power_group); + /* Hubs are automatically enabled for USB_PERSIST, + * no point in creating the attribute file. + */ + if (udev->descriptor.bDeviceClass != USB_CLASS_HUB) + rc = sysfs_add_file_to_group(&dev->kobj, + &dev_attr_persist.attr, + power_group); } return rc; } @@ -238,13 +237,12 @@ static void remove_persist_attributes(struct device *dev) &dev_attr_persist.attr, power_group); } - #else #define add_persist_attributes(dev) 0 #define remove_persist_attributes(dev) do {} while (0) -#endif /* CONFIG_USB_PERSIST */ +#endif /* CONFIG_PM */ #ifdef CONFIG_USB_SUSPEND |