2023-02-20 18:06:43

by Ziyang Huang

[permalink] [raw]
Subject: [PATCH] usb: dwc2: drd: fix inconsistent mode if role-switch-default-mode="host"

Some boards might use USB-A female connector for USB ports, however,
the port could be connected to a dual-mode USB controller, making it
also behaves as a peripheral device if male-to-male cable is connected.

In this case, the dts looks like this:

&usb0 {
status = "okay";
dr_mode = "otg";
usb-role-switch;
role-switch-default-mode = "host";
};

After boot, dwc2_ovr_init() sets GOTGCTL to GOTGCTL_AVALOVAL and call
dwc2_force_mode() with parameter host=false, which causes inconsistent
mode - The hardware is in peripheral mode while the kernel status is
in host mode.

What we can do now is to call dwc2_drd_role_sw_set() to switch to
device mode, and everything should work just fine now, even switching
back to none(default) mode afterwards.

Fixes: e14acb876985 ("usb: dwc2: drd: add role-switch-default-node support")
Signed-off-by: hzy <[email protected]>
---
drivers/usb/dwc2/drd.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc2/drd.c b/drivers/usb/dwc2/drd.c
index d8d6493bc457..a8605b02115b 100644
--- a/drivers/usb/dwc2/drd.c
+++ b/drivers/usb/dwc2/drd.c
@@ -35,7 +35,8 @@ static void dwc2_ovr_init(struct dwc2_hsotg *hsotg)

spin_unlock_irqrestore(&hsotg->lock, flags);

- dwc2_force_mode(hsotg, (hsotg->dr_mode == USB_DR_MODE_HOST));
+ dwc2_force_mode(hsotg, (hsotg->dr_mode == USB_DR_MODE_HOST) ||
+ (hsotg->role_sw_default_mode == USB_DR_MODE_HOST));
}

static int dwc2_ovr_avalid(struct dwc2_hsotg *hsotg, bool valid)
--
2.34.1



2023-02-20 18:59:31

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH] usb: dwc2: drd: fix inconsistent mode if role-switch-default-mode="host"

On Tue, Feb 21, 2023 at 02:05:35AM +0800, hzy wrote:
> Some boards might use USB-A female connector for USB ports, however,
> the port could be connected to a dual-mode USB controller, making it
> also behaves as a peripheral device if male-to-male cable is connected.
>
> In this case, the dts looks like this:
>
> &usb0 {
> status = "okay";
> dr_mode = "otg";
> usb-role-switch;
> role-switch-default-mode = "host";
> };
>
> After boot, dwc2_ovr_init() sets GOTGCTL to GOTGCTL_AVALOVAL and call
> dwc2_force_mode() with parameter host=false, which causes inconsistent
> mode - The hardware is in peripheral mode while the kernel status is
> in host mode.
>
> What we can do now is to call dwc2_drd_role_sw_set() to switch to
> device mode, and everything should work just fine now, even switching
> back to none(default) mode afterwards.
>
> Fixes: e14acb876985 ("usb: dwc2: drd: add role-switch-default-node support")
> Signed-off-by: hzy <[email protected]>

Signed-off-by does not match your "From:" line of your patch :(

Please fix up and use the correct name here as our documentation asks
for.

thanks,

greg k-h