On Monday 27 April 2009, Alan Stern wrote:
> This patch (as1237) changes the way the PCI host controller drivers
> avoid retaining bogus hardware states during resume-from-hibernation.
> Previously we had reset the hardware as part of preparing to reinstate
> the memory image. But we can do better now with the new PM framework,
> since we know exactly which resume operations are from hibernation.
>
> The pci_resume method is changed to accept a flag indicating whether
> the system is resuming from hibernation. When this flag is set, the
> drivers will reset the hardware to get rid of any existing state.
>
> Similarly, the pci_suspend method is changed to remove the
> pm_message_t argument. It's no longer needed, since no special action
> has to be taken when preparing to reinstate the memory image.
>
> Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
This one looks good too.
Acked-by: Rafael J. Wysocki <rjw@xxxxxxx>
> ---
>
> Index: usb-2.6/drivers/usb/core/hcd.h
> ===================================================================
> --- usb-2.6.orig/drivers/usb/core/hcd.h
> +++ usb-2.6/drivers/usb/core/hcd.h
> @@ -182,10 +182,10 @@ struct hc_driver {
> * a whole, not just the root hub; they're for PCI bus glue.
> */
> /* called after suspending the hub, before entering D3 etc */
> - int (*pci_suspend) (struct usb_hcd *hcd, pm_message_t message);
> + int (*pci_suspend)(struct usb_hcd *hcd);
>
> /* called after entering D0 (etc), before resuming the hub */
> - int (*pci_resume) (struct usb_hcd *hcd);
> + int (*pci_resume)(struct usb_hcd *hcd, bool hibernated);
>
> /* cleanly make HCD stop writing memory and doing I/O */
> void (*stop) (struct usb_hcd *hcd);
> Index: usb-2.6/drivers/usb/core/hcd-pci.c
> ===================================================================
> --- usb-2.6.orig/drivers/usb/core/hcd-pci.c
> +++ usb-2.6/drivers/usb/core/hcd-pci.c
> @@ -237,7 +237,7 @@ static int hcd_pci_suspend(struct device
> return retval;
>
> if (hcd->driver->pci_suspend) {
> - retval = hcd->driver->pci_suspend(hcd, PMSG_SUSPEND);
> + retval = hcd->driver->pci_suspend(hcd);
> suspend_report_result(hcd->driver->pci_suspend, retval);
> if (retval)
> return retval;
> @@ -344,7 +344,7 @@ static int resume_common(struct device *
> clear_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
>
> if (hcd->driver->pci_resume) {
> - retval = hcd->driver->pci_resume(hcd);
> + retval = hcd->driver->pci_resume(hcd, hibernated);
> if (retval) {
> dev_err(dev, "PCI post-resume error %d!\n", retval);
> usb_hc_died(hcd);
> Index: usb-2.6/drivers/usb/host/ehci-pci.c
> ===================================================================
> --- usb-2.6.orig/drivers/usb/host/ehci-pci.c
> +++ usb-2.6/drivers/usb/host/ehci-pci.c
> @@ -268,7 +268,7 @@ done:
> * Also they depend on separate root hub suspend/resume.
> */
>
> -static int ehci_pci_suspend(struct usb_hcd *hcd, pm_message_t message)
> +static int ehci_pci_suspend(struct usb_hcd *hcd)
> {
> struct ehci_hcd *ehci = hcd_to_ehci(hcd);
> unsigned long flags;
> @@ -293,12 +293,6 @@ static int ehci_pci_suspend(struct usb_h
> ehci_writel(ehci, 0, &ehci->regs->intr_enable);
> (void)ehci_readl(ehci, &ehci->regs->intr_enable);
>
> - /* make sure snapshot being resumed re-enumerates everything */
> - if (message.event == PM_EVENT_PRETHAW) {
> - ehci_halt(ehci);
> - ehci_reset(ehci);
> - }
> -
> clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
> bail:
> spin_unlock_irqrestore (&ehci->lock, flags);
> @@ -309,7 +303,7 @@ static int ehci_pci_suspend(struct usb_h
> return rc;
> }
>
> -static int ehci_pci_resume(struct usb_hcd *hcd)
> +static int ehci_pci_resume(struct usb_hcd *hcd, bool hibernated)
> {
> struct ehci_hcd *ehci = hcd_to_ehci(hcd);
> struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
> @@ -322,10 +316,12 @@ static int ehci_pci_resume(struct usb_hc
> /* Mark hardware accessible again as we are out of D3 state by now */
> set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
>
> - /* If CF is still set, we maintained PCI Vaux power.
> + /* If CF is still set and we aren't resuming from hibernation
> + * then we maintained PCI Vaux power.
> * Just undo the effect of ehci_pci_suspend().
> */
> - if (ehci_readl(ehci, &ehci->regs->configured_flag) == FLAG_CF) {
> + if (ehci_readl(ehci, &ehci->regs->configured_flag) == FLAG_CF &&
> + !hibernated) {
> int mask = INTR_MASK;
>
> if (!hcd->self.root_hub->do_remote_wakeup)
> @@ -335,7 +331,6 @@ static int ehci_pci_resume(struct usb_hc
> return 0;
> }
>
> - ehci_dbg(ehci, "lost power, restarting\n");
> usb_root_hub_lost_power(hcd->self.root_hub);
>
> /* Else reset, to cope with power loss or flush-to-storage
> Index: usb-2.6/drivers/usb/host/ohci-pci.c
> ===================================================================
> --- usb-2.6.orig/drivers/usb/host/ohci-pci.c
> +++ usb-2.6/drivers/usb/host/ohci-pci.c
> @@ -372,7 +372,7 @@ static int __devinit ohci_pci_start (str
>
> #ifdef CONFIG_PM
>
> -static int ohci_pci_suspend (struct usb_hcd *hcd, pm_message_t message)
> +static int ohci_pci_suspend(struct usb_hcd *hcd)
> {
> struct ohci_hcd *ohci = hcd_to_ohci (hcd);
> unsigned long flags;
> @@ -394,10 +394,6 @@ static int ohci_pci_suspend (struct usb_
> ohci_writel(ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
> (void)ohci_readl(ohci, &ohci->regs->intrdisable);
>
> - /* make sure snapshot being resumed re-enumerates everything */
> - if (message.event == PM_EVENT_PRETHAW)
> - ohci_usb_reset(ohci);
> -
> clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
> bail:
> spin_unlock_irqrestore (&ohci->lock, flags);
> @@ -406,9 +402,14 @@ static int ohci_pci_suspend (struct usb_
> }
>
>
> -static int ohci_pci_resume (struct usb_hcd *hcd)
> +static int ohci_pci_resume(struct usb_hcd *hcd, bool hibernated)
> {
> set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
> +
> + /* Make sure resume from hibernation re-enumerates everything */
> + if (hibernated)
> + ohci_usb_reset(hcd_to_ohci(hcd));
> +
> ohci_finish_controller_resume(hcd);
> return 0;
> }
> Index: usb-2.6/drivers/usb/host/uhci-hcd.c
> ===================================================================
> --- usb-2.6.orig/drivers/usb/host/uhci-hcd.c
> +++ usb-2.6/drivers/usb/host/uhci-hcd.c
> @@ -769,7 +769,7 @@ static int uhci_rh_resume(struct usb_hcd
> return rc;
> }
>
> -static int uhci_pci_suspend(struct usb_hcd *hcd, pm_message_t message)
> +static int uhci_pci_suspend(struct usb_hcd *hcd)
> {
> struct uhci_hcd *uhci = hcd_to_uhci(hcd);
> int rc = 0;
> @@ -795,10 +795,6 @@ static int uhci_pci_suspend(struct usb_h
>
> /* FIXME: Enable non-PME# remote wakeup? */
>
> - /* make sure snapshot being resumed re-enumerates everything */
> - if (message.event == PM_EVENT_PRETHAW)
> - uhci_hc_died(uhci);
> -
> done_okay:
> clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
> done:
> @@ -806,7 +802,7 @@ done:
> return rc;
> }
>
> -static int uhci_pci_resume(struct usb_hcd *hcd)
> +static int uhci_pci_resume(struct usb_hcd *hcd, bool hibernated)
> {
> struct uhci_hcd *uhci = hcd_to_uhci(hcd);
>
> @@ -820,6 +816,10 @@ static int uhci_pci_resume(struct usb_hc
>
> spin_lock_irq(&uhci->lock);
>
> + /* Make sure resume from hibernation re-enumerates everything */
> + if (hibernated)
> + uhci_hc_died(uhci);
> +
> /* FIXME: Disable non-PME# remote wakeup? */
>
> /* The firmware or a boot kernel may have changed the controller
>
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