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

From: Fabrice Gasnier
Date: Wed Jun 22 2022 - 12:08:03 EST


From: Amelie Delaunay <amelie.delaunay@xxxxxxxxxxx>

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@xxxxxxxxxxx>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx>
---
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);
}

/**
--
2.25.1