From c9f89fa40cf274130b56475175a35af961d4b165 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Tue, 13 Sep 2005 19:57:04 -0700 Subject: [PATCH] [PATCH] remove suspend-path recursion This patch removes some recursion in the CONFIG_USB_SUSPEND logic, which suspended children (of devices or hubs) that weren't already suspended. When it sees such cases, suspend now just fails cleanly. That logic was not needed during system-wide sleep state transitions; and given the current notions of how to manage selective suspend transitions, we don't want it there either. Where it was particularly handy was coping with various limitations of the sysfs "echo -n N > power/state" support. (These include assuming that "N" is always meaningful to the driver; and that drivers can only transition to state N from state zero.) Signed-off-by: David Brownell Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 76 +++++++----------------------------------- 1 file changed, 12 insertions(+), 64 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 61341d2f3c..d3337d9c31 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -453,6 +453,7 @@ static void hub_quiesce(struct usb_hub *hub) { /* stop khubd and related activity */ hub->quiescing = 1; + hub->activating = 0; usb_kill_urb(hub->urb); if (hub->has_indicators) cancel_delayed_work(&hub->leds); @@ -1613,68 +1614,21 @@ static int __usb_suspend_device (struct usb_device *udev, int port1, return 0; } - /* suspend interface drivers; if this is a hub, it - * suspends the child devices - */ + /* all interfaces must already be suspended */ if (udev->actconfig) { int i; for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { struct usb_interface *intf; - struct usb_driver *driver; intf = udev->actconfig->interface[i]; - if (!is_active(intf)) - continue; - if (!intf->dev.driver) - continue; - driver = to_usb_driver(intf->dev.driver); - - if (driver->suspend) { - status = driver->suspend(intf, state); - if (status == 0) - mark_quiesced(intf); - else - dev_err(&intf->dev, - "suspend error %d\n", - status); - } - - /* only drivers with suspend() can ever resume(); - * and after power loss, even they won't. - * bus_rescan_devices() can rebind drivers later. - * - * FIXME the PM core self-deadlocks when unbinding - * drivers during suspend/resume ... everything grabs - * dpm_sem (not a spinlock, ugh). we want to unbind, - * since we know every driver's probe/disconnect works - * even for drivers that can't suspend. - */ - if (!driver->suspend || state.event > PM_EVENT_FREEZE) { -#if 1 - dev_warn(&intf->dev, "resume is unsafe!\n"); -#else - down_write(&usb_bus_type.rwsem); - device_release_driver(&intf->dev); - up_write(&usb_bus_type.rwsem); -#endif + if (is_active(intf)) { + dev_dbg(&intf->dev, "nyet suspended\n"); + return -EBUSY; } } } - /* - * FIXME this needs port power off call paths too, to help force - * USB into the "generic" PM model. At least for devices on - * ports that aren't using ganged switching (usually root hubs). - * - * NOTE: SRP-capable links should adopt more aggressive poweroff - * policies (when HNP doesn't apply) once we have mechanisms to - * turn power back on! (Likely not before 2.7...) - */ - if (state.event > PM_EVENT_FREEZE) { - dev_warn(&udev->dev, "no poweroff yet, suspending instead\n"); - } - /* "global suspend" of the HC-to-USB interface (root hub), or * "selective suspend" of just one hub-device link. */ @@ -1960,26 +1914,20 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg) struct usb_hub *hub = usb_get_intfdata (intf); struct usb_device *hdev = hub->hdev; unsigned port1; - int status; - - /* stop khubd and related activity */ - hub_quiesce(hub); - /* then suspend every port */ + /* fail if children aren't already suspended */ for (port1 = 1; port1 <= hdev->maxchild; port1++) { struct usb_device *udev; udev = hdev->children [port1-1]; - if (!udev) - continue; - down(&udev->serialize); - status = __usb_suspend_device(udev, port1, msg); - up(&udev->serialize); - if (status < 0) - dev_dbg(&intf->dev, "suspend port %d --> %d\n", - port1, status); + if (udev && udev->state != USB_STATE_SUSPENDED) { + dev_dbg(&intf->dev, "port %d nyet suspended\n", port1); + return -EBUSY; + } } + /* stop khubd and related activity */ + hub_quiesce(hub); return 0; } -- 2.39.5