On Wed, Oct 13, 2021 at 11:32:08AM +0800, Yinbo Zhu wrote: > While going into S3 or S4 suspend, an OHCI host controller can > generate interrupt requests if the INTR_SF enable flag is set. The > interrupt handler routine isn't prepared for this and it doesn't turn > off the flag, causing an interrupt storm. > > To fix this problem, make ohci_rh_suspend() always disable INTR_SF > interrupts after processing the done list and the ED unlinks but > before the controller goes into the suspended (non-UsbOperational) > state. There's no reason to leave the flag enabled, since a > suspended controller doesn't generate Start-of-Frame packets. > > Signed-off-by: Yinbo Zhu <zhuyinbo@xxxxxxxxxxx> > --- Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > Change in v6: > 1. Rework the commit log information. > 2. Move the key change code after ohci_work in > ohci_rh_suspend. > > > drivers/usb/host/ohci-hub.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c > index f474f2f..90cee19 100644 > --- a/drivers/usb/host/ohci-hub.c > +++ b/drivers/usb/host/ohci-hub.c > @@ -91,6 +91,9 @@ static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop) > update_done_list(ohci); > ohci_work(ohci); > > + /* All ED unlinks should be finished, no need for SOF interrupts */ > + ohci_writel(ohci, OHCI_INTR_SF, &ohci->regs->intrdisable); > + > /* > * Some controllers don't handle "global" suspend properly if > * there are unsuspended ports. For these controllers, put all > -- > 1.8.3.1 >
