[PATCH v3 1/3] phy_sun4i_usb: set_mode: Allow using set_mode to force end the current session

[Kishon Vijay Abraham I]

On Friday 23 September 2016 07:10 PM, Hans de Goede 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_SESSION and sets MUSB_DEVCTL_BDEVICE) and
> gets stuck in this state.
> 
> Clearing this requires reporting Vbus low for 200 or more ms, but
> on some devices Vbus is simply always high (host-only mode, no Vbus
> control).
> 
> This commit modifies sun4i_usb_phy_set_mode so that it will force
> end the current session when called with the current mode, before this
> commit calling set_mode with the current mode was a nop since id_det
> would stay the same resulting in the detect_work not doing anything.
> 
> This allows the sunxi-musb glue to use sun4i_usb_phy_set_mode to force
> end the current session without changing the mode, to fixup the stuck
> state after a babble error.
> 
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>

merged, thanks.

-Kishon
> ---
> Changes in v2:
> -New patch in v2 of this series replacing the
>  "phy-sun4i-usb: Add sun4i_usb_phy_force_session_end() function"
>  from v1
> Changes in v3:
> -Fix dev_info so that it prints the new-mode instead of the old one
> ---
>  drivers/phy/phy-sun4i-usb.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/phy/phy-sun4i-usb.c b/drivers/phy/phy-sun4i-usb.c
> index 43c0d98..cbd338d 100644
> --- a/drivers/phy/phy-sun4i-usb.c
> +++ b/drivers/phy/phy-sun4i-usb.c
> @@ -437,25 +437,31 @@ static int sun4i_usb_phy_set_mode(struct phy *_phy, enum phy_mode mode)
>  {
>  	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
>  	struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
> +	int new_mode;
>  
>  	if (phy->index != 0)
>  		return -EINVAL;
>  
>  	switch (mode) {
>  	case PHY_MODE_USB_HOST:
> -		data->dr_mode = USB_DR_MODE_HOST;
> +		new_mode = USB_DR_MODE_HOST;
>  		break;
>  	case PHY_MODE_USB_DEVICE:
> -		data->dr_mode = USB_DR_MODE_PERIPHERAL;
> +		new_mode = USB_DR_MODE_PERIPHERAL;
>  		break;
>  	case PHY_MODE_USB_OTG:
> -		data->dr_mode = USB_DR_MODE_OTG;
> +		new_mode = USB_DR_MODE_OTG;
>  		break;
>  	default:
>  		return -EINVAL;
>  	}
>  
> -	dev_info(&_phy->dev, "Changing dr_mode to %d\n", (int)data->dr_mode);
> +	if (new_mode != data->dr_mode) {
> +		dev_info(&_phy->dev, "Changing dr_mode to %d\n", new_mode);
> +		data->dr_mode = new_mode;
> +	}
> +
> +	data->id_det = -1; /* Force reprocessing of id */
>  	data->force_session_end = true;
>  	queue_delayed_work(system_wq, &data->detect, 0);
>  
>