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Message-ID: <dde01219-57f7-3cc2-c4fb-5b6a38bd7a9c@quicinc.com>
Date:   Wed, 26 Apr 2023 06:47:13 +0530
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Subject: Re: [PATCH v2 2/2] usb: gadget: udc: Handle gadget_connect failure
 during bind operation
To:     Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Alan Stern <stern@rowland.harvard.edu>,
        "Geert Uytterhoeven" <geert+renesas@glider.be>,
        Colin Ian King <colin.i.king@gmail.com>,
        Jiantao Zhang <water.zhangjiantao@huawei.com>,
        "Rafael J . Wysocki" <rafael@kernel.org>
CC:     <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <quic_ppratap@quicinc.com>, <quic_wcheng@quicinc.com>,
        <quic_jackp@quicinc.com>, <quic_ugoswami@quicinc.com>
References: <20230328160756.30520-1-quic_kriskura@quicinc.com>
 <20230328160756.30520-3-quic_kriskura@quicinc.com>
Content-Language: en-US
From:   Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>
In-Reply-To: <20230328160756.30520-3-quic_kriskura@quicinc.com>
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Hi Alan, Geert,

  Can you help review and provide comments/approval on the following patch.

Regards,
Krishna,

On 3/28/2023 9:37 PM, Krishna Kurapati wrote:
> In the event, gadget_connect call (which invokes pullup) fails,
> propagate the error to udc bind operation which inturn sends the
> error to configfs. The userspace can then retry enumeartion if
> it chooses to.
> 
> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
> ---
>   drivers/usb/gadget/udc/core.c | 20 ++++++++++++++++----
>   1 file changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
> index 23b0629a8774..975205a1853f 100644
> --- a/drivers/usb/gadget/udc/core.c
> +++ b/drivers/usb/gadget/udc/core.c
> @@ -1051,12 +1051,16 @@ EXPORT_SYMBOL_GPL(usb_gadget_set_state);
>   
>   /* ------------------------------------------------------------------------- */
>   
> -static void usb_udc_connect_control(struct usb_udc *udc)
> +static int usb_udc_connect_control(struct usb_udc *udc)
>   {
> +	int ret;
> +
>   	if (udc->vbus)
> -		usb_gadget_connect(udc->gadget);
> +		ret = usb_gadget_connect(udc->gadget);
>   	else
> -		usb_gadget_disconnect(udc->gadget);
> +		ret = usb_gadget_disconnect(udc->gadget);
> +
> +	return ret;
>   }
>   
>   /**
> @@ -1500,11 +1504,19 @@ static int gadget_bind_driver(struct device *dev)
>   	if (ret)
>   		goto err_start;
>   	usb_gadget_enable_async_callbacks(udc);
> -	usb_udc_connect_control(udc);
> +	ret = usb_udc_connect_control(udc);
> +	if (ret)
> +		goto err_connect_control;
>   
>   	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
>   	return 0;
>   
> + err_connect_control:
> +	usb_gadget_disable_async_callbacks(udc);
> +	if (gadget->irq)
> +		synchronize_irq(gadget->irq);
> +	usb_gadget_udc_stop(udc);
> +
>    err_start:
>   	driver->unbind(udc->gadget);
>