Re: [PATCH] usb: musb: Check for host-mode using is_host_active() on reset interrupt

From: Bin Liu
Date: Mon Oct 09 2017 - 12:04:20 EST


Hi,

On Wed, Sep 27, 2017 at 08:35:22PM +1000, Jonathan Liu wrote:
> The sunxi musb has a bug where sometimes it will generate a babble
> error on device disconnect instead of a disconnect IRQ. When this
> happens the musb controller switches from host mode to device mode
> (it clears MUSB_DEVCTL_HM/MUSB_DEVCTL_SESSION and sets
> MUSB_DEVCTL_BDEVICE) and gets stuck in this state.
>
> The babble error is misdetected as a bus reset because MUSB_DEVCTL_HM
> was cleared.
>
> To fix this, use is_host_active() rather than (devctl & MUSB_DEVCTL_HM)
> to detect babble error so that sunxi musb babble recovery can handle it
> by restoring the mode. This information is provided by the driver logic
> and does not rely on register contents.
>
> Cc: stable@xxxxxxxxxxxxxxx # v4.1+
> Signed-off-by: Jonathan Liu <net147@xxxxxxxxx>

Applied. Thanks.
-Bin.