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 <[email protected]>
---
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
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 <[email protected]>
> ---
Acked-by: Alan Stern <[email protected]>
> 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
>