[Linux-stm32] [PATCH] usb: dwc2: gadget: remove D+ pull-up while no vbus with usb-role-switch

[Minas Harutyunyan]

On 6/22/2022 8:07 PM, Fabrice Gasnier wrote:
> From: Amelie Delaunay <amelie.delaunay at foss.st.com>
> 
> When using usb-role-switch, D+ pull-up is set as soon as DTCL_SFTDISCON is
> cleared, whatever the vbus valid signal state is. The pull-up should not
> be set when vbus isn't present (this is determined by the drd controller).
> 
> This patch ensures that B-Session (so Peripheral role + vbus valid signal)
> is valid before clearing the DCTL_SFTDISCON bit when role switch is used.
> Keep original behavior when usb-role-switch isn't used.
> 
> Signed-off-by: Amelie Delaunay <amelie.delaunay at foss.st.com>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier at foss.st.com>

Acked-by: Minas Harutyunyan <hminas at synopsys.com>

> ---
>   drivers/usb/dwc2/gadget.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> index fe2a58c758610..8b15742d9e8aa 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -3594,7 +3594,8 @@ void dwc2_hsotg_core_disconnect(struct dwc2_hsotg *hsotg)
>   void dwc2_hsotg_core_connect(struct dwc2_hsotg *hsotg)
>   {
>   	/* remove the soft-disconnect and let's go */
> -	dwc2_clear_bit(hsotg, DCTL, DCTL_SFTDISCON);
> +	if (!hsotg->role_sw || (dwc2_readl(hsotg, GOTGCTL) & GOTGCTL_BSESVLD))
> +		dwc2_clear_bit(hsotg, DCTL, DCTL_SFTDISCON);
>   }
>   
>   /**