Subject: Re: [PATCH 4/6] usb/fsl_qe_udc: Fix disconnects reporting during bus reset

From: David Brownell <[email-masked]>
Date: Mon, 17 Nov 2008 17:48:24 -0800

On Tuesday 11 November 2008, Anton Vorontsov wrote:
> Freescale QE UDC controllers can't report the "port change" states,
> so the only way to handle disconnects is to process bus reset
> interrupts. The bus reset can take some time, that is, few irqs.
> Gadgets may print the disconnection events, and this causes few
> repetitive messages in the kernel log.
> 
> This patch fixes the issue by using the usb_state machine, if the
> usb controller has been already reset, just quit the reset irq
> early.
> 
> Signed-off-by: Anton Vorontsov <[email-masked]>

Acked-by: David Brownell <[email-masked]>

Note that the "port change" you reference is more typically
packaged as "VBUS detect" ... often handled with a GPIO.

> ---
>  drivers/usb/gadget/fsl_qe_udc.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/usb/gadget/fsl_qe_udc.c b/drivers/usb/gadget/fsl_qe_udc.c
> index 1789f65..7bb5f36 100644
> --- a/drivers/usb/gadget/fsl_qe_udc.c
> +++ b/drivers/usb/gadget/fsl_qe_udc.c
> @@ -2161,6 +2161,9 @@ static int reset_irq(struct qe_udc *udc)
>  {
>  	unsigned char i;
>  
> +	if (udc->usb_state == USB_STATE_DEFAULT)
> +		return 0;
> +
>  	qe_usb_disable();
>  	out_8(&udc->usb_regs->usb_usadr, 0);
>  
> -- 
> 1.5.6.3
> 
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