We identified a bug where the ST_RC bit in the status register was not being acknowledged after clearing the CTRL_RUN bit in the control register. This could lead to unexpected behavior in the USB gadget drivers.

This patch resolves the issue by adding the necessary code to explicitly acknowledge ST_RC after clearing CTRL_RUN based on the programming sequence, ensuring proper state transition.

Fixes: 49db427232fe ("usb: gadget: Add UDC driver for tegra XUSB device mode controller") Cc: stable@vger.kernel.org Signed-off-by: Wayne Chang waynec@nvidia.com --- drivers/usb/gadget/udc/tegra-xudc.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c index c7fdbc55fb0b..2957316fd3d0 100644 --- a/drivers/usb/gadget/udc/tegra-xudc.c +++ b/drivers/usb/gadget/udc/tegra-xudc.c @@ -1749,6 +1749,10 @@ static int __tegra_xudc_ep_disable(struct tegra_xudc_ep *ep) val = xudc_readl(xudc, CTRL); val &= ~CTRL_RUN; xudc_writel(xudc, val, CTRL); + + val = xudc_readl(xudc, ST); + if (val & ST_RC) + xudc_writel(xudc, ST_RC, ST); }

dev_info(xudc->dev, "ep %u disabled\n", ep->index);