[Linux-stm32] [PATCH 1/1] usb: dwc2: fix STM ID/VBUS detection startup delay in dwc2_driver_probe

[Minas Harutyunyan]

On 12/7/2021 4:45 PM, Amelie Delaunay wrote:
> When activate_stm_id_vb_detection is enabled, ID and Vbus detection relies
> on sensing comparators. This detection needs time to stabilize.
> A delay was already applied in dwc2_resume() when reactivating the
> detection, but it wasn't done in dwc2_probe().
> This patch adds delay after enabling STM ID/VBUS detection. Then, ID state
> is good when initializing gadget and host, and avoid to get a wrong
> Connector ID Status Change interrupt.
> 
> Fixes: a415083a11cc ("usb: dwc2: add support for STM32MP15 SoCs USB OTG HS and FS")
> Signed-off-by: Amelie Delaunay <amelie.delaunay at foss.st.com>

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

> ---
>   drivers/usb/dwc2/platform.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
> index a1feaa09be57..55d7fca6f95c 100644
> --- a/drivers/usb/dwc2/platform.c
> +++ b/drivers/usb/dwc2/platform.c
> @@ -555,6 +555,9 @@ static int dwc2_driver_probe(struct platform_device *dev)
>   		ggpio |= GGPIO_STM32_OTG_GCCFG_IDEN;
>   		ggpio |= GGPIO_STM32_OTG_GCCFG_VBDEN;
>   		dwc2_writel(hsotg, ggpio, GGPIO);
> +
> +		/* ID/VBUS detection startup time */
> +		usleep_range(5000, 7000);
>   	}
>   
>   	retval = dwc2_drd_init(hsotg);