From stern@rowland.harvard.edu Sat Jul 1 19:13:07 2006 Date: Sat, 1 Jul 2006 22:13:04 -0400 (EDT) From: Alan Stern To: Greg KH Subject: [PATCH 12/15] usbcore: fix up device and power state tests Message-ID: This patch (as734) rationalizes the various tests of device state and power states. There are duplications and mistaken tests in several places. Perhaps the most interesting challenge is where the hub driver tests to see that all the child devices are suspended before allowing itself to be suspended. When CONFIG_USB_SUSPEND is set the test is straightforward, since we expect that the children _will_ be suspended. But when CONFIG_USB_SUSPEND isn't set, it's not so clear what should be done. The code compromises by checking the child's power.power_state.event field. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/driver.c | 40 ++++++++++++++++++-------------------- drivers/usb/core/generic.c | 3 -- drivers/usb/core/hub.c | 47 +++++++++------------------------------------ 3 files changed, 29 insertions(+), 61 deletions(-) --- gregkh-2.6.orig/drivers/usb/core/driver.c +++ gregkh-2.6/drivers/usb/core/driver.c @@ -757,11 +757,13 @@ static int suspend_device(struct usb_dev struct usb_device_driver *udriver; int status = 0; + if (udev->state == USB_STATE_NOTATTACHED || + udev->state == USB_STATE_SUSPENDED) + goto done; + if (udev->dev.driver == NULL) goto done; udriver = to_usb_device_driver(udev->dev.driver); - if (udev->dev.power.power_state.event == msg.event) - goto done; status = udriver->suspend(udev, msg); done: @@ -776,14 +778,13 @@ static int resume_device(struct usb_devi struct usb_device_driver *udriver; int status = 0; - if (udev->dev.power.power_state.event == PM_EVENT_ON) + if (udev->state == USB_STATE_NOTATTACHED || + udev->state != USB_STATE_SUSPENDED) goto done; if (udev->dev.driver == NULL) goto done; udriver = to_usb_device_driver(udev->dev.driver); - if (udev->state == USB_STATE_NOTATTACHED) - goto done; status = udriver->resume(udev); done: @@ -798,14 +799,14 @@ static int suspend_interface(struct usb_ struct usb_driver *driver; int status = 0; - if (intf->dev.driver == NULL) + /* with no hardware, USB interfaces only use FREEZE and ON states */ + if (interface_to_usbdev(intf)->state == USB_STATE_NOTATTACHED || + !is_active(intf)) goto done; - driver = to_usb_driver(intf->dev.driver); - - /* with no hardware, USB interfaces only use FREEZE and ON states */ - if (!is_active(intf)) + if (intf->dev.driver == NULL) goto done; + driver = to_usb_driver(intf->dev.driver); if (driver->suspend && driver->resume) { status = driver->suspend(intf, msg); @@ -831,25 +832,16 @@ done: static int resume_interface(struct usb_interface *intf) { struct usb_driver *driver; - struct usb_device *udev; int status = 0; - if (intf->dev.power.power_state.event == PM_EVENT_ON) + if (interface_to_usbdev(intf)->state == USB_STATE_NOTATTACHED || + is_active(intf)) goto done; if (intf->dev.driver == NULL) goto done; - driver = to_usb_driver(intf->dev.driver); - udev = interface_to_usbdev(intf); - if (udev->state == USB_STATE_NOTATTACHED) - goto done; - - /* if driver was suspended, it has a resume method; - * however, sysfs can wrongly mark things as suspended - * (on the "no suspend method" FIXME path above) - */ if (driver->resume) { status = driver->resume(intf); if (status) @@ -904,6 +896,12 @@ int usb_resume_both(struct usb_device *u int i; struct usb_interface *intf; + /* Can't resume if the parent is suspended */ + if (udev->parent && udev->parent->state == USB_STATE_SUSPENDED) { + dev_warn(&udev->dev, "can't resume; parent is suspended\n"); + return -EHOSTUNREACH; + } + status = resume_device(udev); if (status == 0 && udev->actconfig) { for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { --- gregkh-2.6.orig/drivers/usb/core/generic.c +++ gregkh-2.6/drivers/usb/core/generic.c @@ -195,9 +195,6 @@ static int generic_suspend(struct usb_de static int generic_resume(struct usb_device *udev) { - if (udev->state == USB_STATE_NOTATTACHED) - return 0; - return usb_port_resume(udev); } --- gregkh-2.6.orig/drivers/usb/core/hub.c +++ gregkh-2.6/drivers/usb/core/hub.c @@ -1556,26 +1556,6 @@ static int __usb_port_suspend (struct us if (port1 < 0) return port1; - if (udev->state == USB_STATE_SUSPENDED - || udev->state == USB_STATE_NOTATTACHED) { - return 0; - } - - /* all interfaces must already be suspended */ - if (udev->actconfig) { - int i; - - for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { - struct usb_interface *intf; - - intf = udev->actconfig->interface[i]; - if (is_active(intf)) { - dev_dbg(&intf->dev, "nyet suspended\n"); - return -EBUSY; - } - } - } - /* we change the device's upstream USB link, * but root hubs have no upstream USB link. */ @@ -1614,8 +1594,6 @@ static int __usb_port_suspend (struct us int usb_port_suspend(struct usb_device *udev) { #ifdef CONFIG_USB_SUSPEND - if (udev->state == USB_STATE_NOTATTACHED) - return -ENODEV; return __usb_port_suspend(udev, udev->portnum); #else return 0; @@ -1761,24 +1739,17 @@ hub_port_resume(struct usb_hub *hub, int */ int usb_port_resume(struct usb_device *udev) { - int status; - - if (udev->state == USB_STATE_NOTATTACHED) - return -ENODEV; + int status = 0; /* we change the device's upstream USB link, * but root hubs have no upstream USB link. */ if (udev->parent) { #ifdef CONFIG_USB_SUSPEND - if (udev->state == USB_STATE_SUSPENDED) { - // NOTE swsusp may bork us, device state being wrong... - // NOTE this fails if parent is also suspended... - status = hub_port_resume(hdev_to_hub(udev->parent), - udev->portnum, udev); - } else + // NOTE this fails if parent is also suspended... + status = hub_port_resume(hdev_to_hub(udev->parent), + udev->portnum, udev); #endif - status = 0; } else status = finish_port_resume(udev); if (status < 0) @@ -1821,12 +1792,14 @@ static int hub_suspend(struct usb_interf struct usb_device *udev; udev = hdev->children [port1-1]; - if (udev && (udev->dev.power.power_state.event - == PM_EVENT_ON + if (udev && msg.event == PM_EVENT_SUSPEND && #ifdef CONFIG_USB_SUSPEND - || udev->state != USB_STATE_SUSPENDED + udev->state != USB_STATE_SUSPENDED +#else + udev->dev.power.power_state.event + == PM_EVENT_ON #endif - )) { + ) { dev_dbg(&intf->dev, "port %d nyet suspended\n", port1); return -EBUSY; }