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> --- 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
