Hi,
On Tue, Oct 17, 2023, Alexander Stein wrote:
> From: Markus Niebel <Markus.Niebel@xxxxxxxxxxxxxxx>
>
> When we have a role switch device attached, we should not configure our
> initial role. Leave this up to the role switch device, that should
> detect and signal the initial role.
>
> This fixes situations where a Type-A plug is connected already when the
> driver is loaded but the default role is set to none or device. In this
> case only an disconnect / reconnect gets the correct mode.
If the default role is none, why isn't there a notification to update
the role on initialization from the connector? The current role should
not be none.
BR,
Thinh
>
> Signed-off-by: Markus Niebel <Markus.Niebel@xxxxxxxxxxxxxxx>
> Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
> ---
> I couldn't find any information whether USB role switch drivers are
> supposed to call usb_role_switch_set_role() during their probe.
> But this seems sensible, otherwise the actual/initial state is unknown.
>
> drivers/usb/dwc3/drd.c | 13 +++++--------
> 1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
> index 039bf241769af..1c2e504a5d8ba 100644
> --- a/drivers/usb/dwc3/drd.c
> +++ b/drivers/usb/dwc3/drd.c
> @@ -496,15 +496,8 @@ static enum usb_role dwc3_usb_role_switch_get(struct usb_role_switch *sw)
> static int dwc3_setup_role_switch(struct dwc3 *dwc)
> {
> struct usb_role_switch_desc dwc3_role_switch = {NULL};
> - u32 mode;
>
> dwc->role_switch_default_mode = usb_get_role_switch_default_mode(dwc->dev);
> - if (dwc->role_switch_default_mode == USB_DR_MODE_HOST) {
> - mode = DWC3_GCTL_PRTCAP_HOST;
> - } else {
> - dwc->role_switch_default_mode = USB_DR_MODE_PERIPHERAL;
> - mode = DWC3_GCTL_PRTCAP_DEVICE;
> - }
>
> dwc3_role_switch.fwnode = dev_fwnode(dwc->dev);
> dwc3_role_switch.set = dwc3_usb_role_switch_set;
> @@ -526,7 +519,11 @@ static int dwc3_setup_role_switch(struct dwc3 *dwc)
> }
> }
>
> - dwc3_set_mode(dwc, mode);
> + /*
> + * usb_role_switch should implement initial detection and call
> + * dwc3_usb_role_switch_set to get the state machine running
> + */
> +
> return 0;
> }
> #else
> --
> 2.34.1
>
