hi Alan:
2015-01-19 0:49 GMT+08:00 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>:
> On Sun, 18 Jan 2015, vichy wrote:
>
>> after tracing the source, I only can find the ehci_suspend is called
>> when system hibernate/suspend.
>> rpm_suspend use below method to find out suspend callback
>> if (dev->pm_domain)
>> callback = dev->pm_domain->ops.runtime_suspend;
>> else if (dev->type && dev->type->pm)
>> callback = dev->type->pm->runtime_suspend;
>> else if (dev->class && dev->class->pm)
>> callback = dev->class->pm->runtime_suspend;
>> else if (dev->bus && dev->bus->pm)
>> callback = dev->bus->pm->runtime_suspend;
>> else
>> callback = NULL;
>>
>> ehci_suspend doesn't register any one of above function.
>
> ehci_pci_init() in ehci_pci.c stores ehci_suspend in
> ehci_pci_hc_driver.pci_suspend. That pointer is called by
> suspend_common() in hcd-pci.c, which is called by both
> hcd_pci_suspend() and hcd_pci_runtime_suspend().
I have several questions:
a.
in ehci-pci driver, the runtime suspend is register in the driver
structure, driver->pm, like below.
static struct pci_driver ehci_pci_driver = {
...................
.probe = usb_hcd_pci_probe,
.remove = usb_hcd_pci_remove,
.shutdown = usb_hcd_pci_shutdown,
#ifdef CONFIG_PM_SLEEP
.driver = {
.pm = &usb_hcd_pci_pm_ops
},
#endif
};
But rpm_suspend search runtime suspend from device structure.
like dev->pm_domain, dev->type, dev->class, dev->bus, etc.
Why hcd_pci_runtime_suspend will be called?
b.
Contrary to pci system, in ehci-platfomr.c, there is no any runtime
suspend call back register in ehci_platform_pm_ops.
Could we get the conclusion that ehci controller will NOT be suspended
when all device on the root hub and root hub are suspended?
Sincerely appreciate your kind help,
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