Hi Tony,
Sorry for my late response.
On Mon, Nov 25, 2019 at 07:41:51PM -0800, Tony Lindgren wrote:
> When disconnected as USB B-device, we sometimes get a suspend interrupt
> after disconnect interrupt. In that case we have devctl set to 99 with
> VBUS still valid and musb_pm_runtime_check_session() wrongly things we
> have an active session. We have no other interrupts after disconnect
> coming in this case at least with the omap2430 glue.
I don't have an omap2430 platform to test, but its musb doesn't generate
DISCONNECT interrupt at all when disconnected from USB host in any case?
It is a surprise, the musb core driver expects the DISCONNECT interrupt
after VBUS is lost and relies on it to tear down the gadget driver and
the state machine. I am wondering how its USB is functional without the
DISCONNECT event...
-Bin.
>
> Let's fix the issue by checking the interrupt status again with
> delayed work for the devctl 99 case. In the suspend after disconnect
> case the devctl session bit has cleared by then and musb can idle.
> For a typical USB B-device connect case we just continue with normal
> interrupts.
>
> Cc: Merlijn Wajer <merlijn@xxxxxxxxxx>
> Cc: Pavel Machek <pavel@xxxxxx>
> Cc: Sebastian Reichel <sre@xxxxxxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> ---
> drivers/usb/musb/musb_core.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> --- a/drivers/usb/musb/musb_core.c
> +++ b/drivers/usb/musb/musb_core.c
> @@ -1943,6 +1943,9 @@ ATTRIBUTE_GROUPS(musb);
> #define MUSB_QUIRK_B_INVALID_VBUS_91 (MUSB_DEVCTL_BDEVICE | \
> (2 << MUSB_DEVCTL_VBUS_SHIFT) | \
> MUSB_DEVCTL_SESSION)
> +#define MUSB_QUIRK_B_DISCONNECT_99 (MUSB_DEVCTL_BDEVICE | \
> + (3 << MUSB_DEVCTL_VBUS_SHIFT) | \
> + MUSB_DEVCTL_SESSION)
> #define MUSB_QUIRK_A_DISCONNECT_19 ((3 << MUSB_DEVCTL_VBUS_SHIFT) | \
> MUSB_DEVCTL_SESSION)
>
> @@ -1965,6 +1968,11 @@ static void musb_pm_runtime_check_session(struct musb *musb)
> s = MUSB_DEVCTL_FSDEV | MUSB_DEVCTL_LSDEV |
> MUSB_DEVCTL_HR;
> switch (devctl & ~s) {
> + case MUSB_QUIRK_B_DISCONNECT_99:
> + musb_dbg(musb, "Poll devctl in case of suspend after disconnect\n");
> + schedule_delayed_work(&musb->irq_work,
> + msecs_to_jiffies(1000));
> + break;
> case MUSB_QUIRK_B_INVALID_VBUS_91:
> if (musb->quirk_retries && !musb->flush_irq_work) {
> musb_dbg(musb,
> --
> 2.24.0
