usb: ohci: disable start-of-frame interrupt in ohci_rh_suspend

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.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn>
Link: https://lore.kernel.org/r/1634095928-29639-1-git-send-email-zhuyinbo@loongson.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index f474f2f..90cee19 100644 (file)
--- a/drivers/usb/host/ohci-hub.c
+++ b/drivers/usb/host/ohci-hub.c
@@ -91,6 +91,9 @@ __acquires(ohci->lock)
        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