Subject: Re: [PATCH v4 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue
 available space
To: changbin.du@intel.com, balbi@kernel.org
References: <1460459419-9487-1-git-send-email-changbin.du@intel.com>
 <1460459419-9487-3-git-send-email-changbin.du@intel.com>
Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Message-ID: <570CF0E1.1010601@cogentembedded.com>
Date: Tue, 12 Apr 2016 15:58:09 +0300
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Hello.

On 4/12/2016 2:10 PM, changbin.du@intel.com wrote:

> From: "Du, Changbin" <changbin.du@intel.com>
>
> For DWC3 USB controller, the Global Debug Queue/FIFO Space Available
> Register(GDBGFIFOSPACE) can be used to dump FIFO/Queue available space.

    Space needed before (.

> This can be used to check some special issues, like whether data is
> successfully copied from memory to fifo when a trb is blocked.
>
> Signed-off-by: Du, Changbin <changbin.du@intel.com>
> ---
> v4:
>    Do not fail silently, but print error.
[...]
> diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
> index 615d4dc..83e5bc1 100644
> --- a/drivers/usb/dwc3/debugfs.c
> +++ b/drivers/usb/dwc3/debugfs.c
[...]
> @@ -642,10 +681,15 @@ void dwc3_debugfs_init(struct dwc3 *dwc)
>   	dwc->regset->nregs = ARRAY_SIZE(dwc3_regs);
>   	dwc->regset->base = dwc->regs;
>
> +

    Why?

>   	file = debugfs_create_regset32("regdump", S_IRUGO, root, dwc->regset);
>   	if (!file)
>   		dev_err(dwc->dev, "Can't create debugfs regdump\n");
>
> +	file = debugfs_create_file("fifo", S_IRUGO, root, dwc, &dwc3_fifo_fops);
> +	if (!file)
> +		dev_err(dwc->dev, "Can't create debugfs fifo\n");
> +
>   	if (IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE)) {
>   		file = debugfs_create_file("mode", S_IRUGO | S_IWUSR, root,
>   				dwc, &dwc3_mode_fops);

MBR, Sergei