On Wednesday, February 16, 2011, Alan Stern wrote:
> On Wed, 16 Feb 2011, Rafael J. Wysocki wrote:
>
> > Unfortunately, it doesn't work on my Acer Ferrari One. The problem is that
> > hcd_pci_suspend() fails for the EHCI controller, apparently because the root
> > hub is not suspended. Do root hubs need both class suspend and bus type
> > suspend to work at the same time?
>
> No, only the bus type suspend method is needed.
Bus type or device type? It appears to be the latter from reading the code
(although admittedly not too thorough).
> Can you provide the dmesg log using a kernel built with CONFIG_USB_DEBUG?
Well, I know what the problem is.
USB defines usb_device_type pointing to usb_device_pm_ops that provides
system-wide PM callbacks only and usb_bus_type pointing to
usb_bus_pm_ops that provides runtime PM callbacks only. So it looks like
we should move either the system-wide PM callbacks to usb_bus_pm_ops,
or the runtime PM callbacks to usb_device_pm_ops.
FWIW, the appended patch helps on my test machine, but I'm not sure if it
is the right thing to do.
Apart from this I think the order of checks introduced by the $subject patch
should be:
(1) If dev->class != NULL and dev->class->pm != NULL, use dev->class,
or otherwise
(2) if dev->type != NULL and dev->type->pm != NULL, use dev->type,
or otherwise
(3) use dev->bus (if present).
as that would allow classes and device types to override bus type PM
callbacks if they wish to.
Thanks,
Rafael
---
drivers/usb/core/driver.c | 15 +++------------
drivers/usb/core/usb.c | 5 +++++
drivers/usb/core/usb.h | 18 ++++++++++++++++++
3 files changed, 26 insertions(+), 12 deletions(-)
Index: linux-2.6/drivers/usb/core/driver.c
===================================================================
--- linux-2.6.orig/drivers/usb/core/driver.c
+++ linux-2.6/drivers/usb/core/driver.c
@@ -1646,7 +1646,7 @@ static int autosuspend_check(struct usb_
return 0;
}
-static int usb_runtime_suspend(struct device *dev)
+int usb_runtime_suspend(struct device *dev)
{
struct usb_device *udev = to_usb_device(dev);
int status;
@@ -1662,7 +1662,7 @@ static int usb_runtime_suspend(struct de
return status;
}
-static int usb_runtime_resume(struct device *dev)
+int usb_runtime_resume(struct device *dev)
{
struct usb_device *udev = to_usb_device(dev);
int status;
@@ -1674,7 +1674,7 @@ static int usb_runtime_resume(struct dev
return status;
}
-static int usb_runtime_idle(struct device *dev)
+int usb_runtime_idle(struct device *dev)
{
struct usb_device *udev = to_usb_device(dev);
@@ -1686,19 +1686,10 @@ static int usb_runtime_idle(struct devic
return 0;
}
-static const struct dev_pm_ops usb_bus_pm_ops = {
- .runtime_suspend = usb_runtime_suspend,
- .runtime_resume = usb_runtime_resume,
- .runtime_idle = usb_runtime_idle,
-};
-
#endif /* CONFIG_USB_SUSPEND */
struct bus_type usb_bus_type = {
.name = "usb",
.match = usb_device_match,
.uevent = usb_uevent,
-#ifdef CONFIG_USB_SUSPEND
- .pm = &usb_bus_pm_ops,
-#endif
};
Index: linux-2.6/drivers/usb/core/usb.h
===================================================================
--- linux-2.6.orig/drivers/usb/core/usb.h
+++ linux-2.6/drivers/usb/core/usb.h
@@ -77,6 +77,9 @@ static inline int usb_port_resume(struct
extern void usb_autosuspend_device(struct usb_device *udev);
extern int usb_autoresume_device(struct usb_device *udev);
extern int usb_remote_wakeup(struct usb_device *dev);
+extern int usb_runtime_suspend(struct device *dev);
+extern int usb_runtime_resume(struct device *dev);
+extern int usb_runtime_idle(struct device *dev);
#else
@@ -90,6 +93,21 @@ static inline int usb_remote_wakeup(stru
{
return 0;
}
+
+static inline int usb_runtime_suspend(struct device *dev)
+{
+ return 0;
+}
+
+static inline int usb_runtime_resume(struct device *dev)
+{
+ return 0;
+}
+
+static inline int usb_runtime_idle(struct device *dev)
+{
+ return 0;
+}
#endif
Index: linux-2.6/drivers/usb/core/usb.c
===================================================================
--- linux-2.6.orig/drivers/usb/core/usb.c
+++ linux-2.6/drivers/usb/core/usb.c
@@ -315,6 +315,11 @@ static const struct dev_pm_ops usb_devic
.thaw = usb_dev_thaw,
.poweroff = usb_dev_poweroff,
.restore = usb_dev_restore,
+#ifdef CONFIG_USB_SUSPEND
+ .runtime_suspend = usb_runtime_suspend,
+ .runtime_resume = usb_runtime_resume,
+ .runtime_idle = usb_runtime_idle,
+#endif
};
#endif /* CONFIG_PM */
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