Hi,
I have a dumb question about enabling EHCI runtime PM with PCI
subsystem. It seems core code in hci-pci.c provides the runtime call
backs in usb_hcd_pci_pm_ops. But I don't see that being used in case of
EHCI suspend/resume.
I must have missed something, can someone explain how this should work?
On our platform, we need to put EHCI in PCI D0i3 hot when we suspend
root hub so that the block can be put into low power mode. I guess we
also need platform specific functions to set the PCI Dx state during
runtime suspend.
It seems we can add the following to schedule PCI runtime PM calls by:
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -301,8 +301,10 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
if (ehci->has_otg && ehci->otg_suspend)
rc = ehci->otg_suspend(hcd);
-
spin_unlock_irq (&ehci->lock);
+ ehci_dbg(ehci, "rpm suspend\n");
+ pm_runtime_put_sync(ehci_to_hcd(ehci)->self.controller);
+ pm_schedule_suspend(ehci_to_hcd(ehci)->self.controller, 0);
/* ehci_work() may have re-enabled the watchdog timer, which we
do not
* want, and so we must delete any pending watchdog timer
events. @@ -322,6 +324,9 @@ static int ehci_bus_resume (struct usb_hcd
*hcd) u8 resume_needed = 0;
int rc = 0;
+ ehci_dbg(ehci, "rpm resume bus\n");
+ pm_runtime_get_sync(ehci_to_hcd(ehci)->self.controller);
+
if (time_before (jiffies, ehci->next_statechange))
msleep(5);
spin_lock_irq (&ehci->lock);
--
Thanks
Jacob
(from Linux laptop)
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