[Linux-stm32] [PATCH 3/3] usb: dwc2: drd: reset current session before setting the new one

[Minas Harutyunyan]

On 10/5/2021 1:53 PM, Amelie Delaunay wrote:
> If role is changed without the "none" step, A- and B- valid session could
> be set at the same time. It is an issue.
> This patch resets A-session if role switch sets B-session, and resets
> B-session if role switch sets A-session.
> Then, it is possible to change the role without the "none" step.
> 
> Fixes: 17f934024e84 ("usb: dwc2: override PHY input signals with usb role switch support")
> Signed-off-by: Amelie Delaunay <amelie.delaunay at foss.st.com>

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

> ---
>   drivers/usb/dwc2/drd.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/dwc2/drd.c b/drivers/usb/dwc2/drd.c
> index 99672360f34b..aa6eb76f64dd 100644
> --- a/drivers/usb/dwc2/drd.c
> +++ b/drivers/usb/dwc2/drd.c
> @@ -40,6 +40,7 @@ static int dwc2_ovr_avalid(struct dwc2_hsotg *hsotg, bool valid)
>   	    (!valid && !(gotgctl & GOTGCTL_ASESVLD)))
>   		return -EALREADY;
>   
> +	gotgctl &= ~GOTGCTL_BVALOVAL;
>   	if (valid)
>   		gotgctl |= GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL;
>   	else
> @@ -58,6 +59,7 @@ static int dwc2_ovr_bvalid(struct dwc2_hsotg *hsotg, bool valid)
>   	    (!valid && !(gotgctl & GOTGCTL_BSESVLD)))
>   		return -EALREADY;
>   
> +	gotgctl &= ~GOTGCTL_AVALOVAL;
>   	if (valid)
>   		gotgctl |= GOTGCTL_BVALOVAL | GOTGCTL_VBVALOVAL;
>   	else
>