Subject: [PATCH 2/2] musb: sunxi: Set state to A_WAIT_VRISE when enabling VBus

From: [email-masked] (Bin Liu)
Date: Fri, 13 May 2016 13:35:02 -0500

Hi,

On Thu, May 12, 2016 at 08:31:09PM +0200, Hans de Goede wrote:
> When the board is powering attached usb devices via the otg port
> sometimes / on some devices it takes slightly too long for the VBus
> detection code in phy-sun4i-usb.c to signal that VBus is high after
> enabling VBus and the musb hardware signals a MUSB_INTR_VBUSERROR
> interrupt.
> 
> This commit sets the otg state to A_WAIT_VRISE upon enabling Vbus
> making musb_stage0_irq() ignore the first VBUSERR_RETRY_COUNT
> VBUSERROR interrupts, fixing connection issues in these cases.
> 
> Signed-off-by: Hans de Goede <[email-masked]>
> ---
>  drivers/usb/musb/sunxi.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/musb/sunxi.c b/drivers/usb/musb/sunxi.c
> index 2c33d9b..2ee48fb 100644
> --- a/drivers/usb/musb/sunxi.c
> +++ b/drivers/usb/musb/sunxi.c
> @@ -112,7 +112,7 @@ static void sunxi_musb_work(struct work_struct *work)
>  		if (test_bit(SUNXI_MUSB_FL_HOSTMODE, &glue->flags)) {
>  			set_bit(SUNXI_MUSB_FL_VBUS_ON, &glue->flags);
>  			musb->xceiv->otg->default_a = 1;
> -			musb->xceiv->otg->state = OTG_STATE_A_IDLE;
> +			musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
>  			MUSB_HST_MODE(musb);
>  			devctl |= MUSB_DEVCTL_SESSION;
>  		} else {
> @@ -145,9 +145,10 @@ static void sunxi_musb_set_vbus(struct musb *musb, int is_on)
>  {
>  	struct sunxi_glue *glue = dev_get_drvdata(musb->controller->parent);
>  
> -	if (is_on)
> +	if (is_on) {
>  		set_bit(SUNXI_MUSB_FL_VBUS_ON, &glue->flags);
> -	else
> +		musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;

Why this has to be set in both sunxi_musb_work() and here? Only setting
it in the work is not efficient?

Regards,
-Bin.

> +	} else
>  		clear_bit(SUNXI_MUSB_FL_VBUS_ON, &glue->flags);
>  
>  	schedule_work(&glue->work);
> @@ -325,6 +326,7 @@ static int sunxi_set_mode(struct musb *musb, u8 mode)
>  		set_bit(SUNXI_MUSB_FL_PHY_ON, &glue->flags);
>  		/* Stop musb work from turning vbus off again */
>  		set_bit(SUNXI_MUSB_FL_VBUS_ON, &glue->flags);
> +		musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
>  	}
>  
>  	return 0;
> -- 
> 2.7.4
>