From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [RFC][PATCH 2/2] PM: Make system-wide PM and runtime PM handle subsystems consistently Date: Wed, 16 Feb 2011 22:47:49 +0100 Message-ID: <201102162247.49924.rjw__25836.4454065033$1297930423$gmane$org@sisk.pl> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: Alan Stern Cc: Mark Brown , LKML , Grant Likely , Linux-pm mailing list List-Id: linux-pm@vger.kernel.org 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 */