linux-kernel - Re: [RFC PATCH] usb: dwc3: fix maximum

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <6dff8574-e649-7a5c-4d80-c3fe6ddd6645@synopsys.com>
Date:   Thu, 9 Jul 2020 22:17:27 +0000
From:   Thinh Nguyen <Thinh.Nguyen@...opsys.com>
To:     Chunfeng Yun <chunfeng.yun@...iatek.com>,
        Felipe Balbi <balbi@...nel.org>
CC:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        "linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-mediatek@...ts.infradead.org" 
        <linux-mediatek@...ts.infradead.org>
Subject: Re: [RFC PATCH] usb: dwc3: fix maximum_speed check for usb2.0-only
 core

Hi,

Chunfeng Yun wrote:
> The maximum_speed will be USB_SPEED_SUPER_PLUS, but the
> maximum_speed check for usb2.0-only core doesn't consider it,
> so fix it, and move the ckeck into dwc3_check_params().
>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@...iatek.com>
> ---
> Note:
>
> When I look at the code, find that this may be a problem, but no
> platform to test it.
> ---
>   drivers/usb/dwc3/core.c | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 25c686a7..ffd5ab3 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -930,13 +930,6 @@ static int dwc3_core_init(struct dwc3 *dwc)
>   	 */
>   	dwc3_writel(dwc->regs, DWC3_GUID, LINUX_VERSION_CODE);
>   
> -	/* Handle USB2.0-only core configuration */
> -	if (DWC3_GHWPARAMS3_SSPHY_IFC(dwc->hwparams.hwparams3) ==
> -			DWC3_GHWPARAMS3_SSPHY_IFC_DIS) {
> -		if (dwc->maximum_speed == USB_SPEED_SUPER)
> -			dwc->maximum_speed = USB_SPEED_HIGH;
> -	}
> -
>   	ret = dwc3_phy_setup(dwc);
>   	if (ret)
>   		goto err0;
> @@ -1426,6 +1419,13 @@ static void dwc3_check_params(struct dwc3 *dwc)
>   
>   		break;
>   	}
> +
> +	/* Handle USB2.0-only core configuration */
> +	if (DWC3_GHWPARAMS3_SSPHY_IFC(dwc->hwparams.hwparams3) ==
> +			DWC3_GHWPARAMS3_SSPHY_IFC_DIS) {
> +		if (dwc->maximum_speed > USB_SPEED_HIGH)
> +			dwc->maximum_speed = USB_SPEED_HIGH;
> +	}
>   }
>   
>   static int dwc3_probe(struct platform_device *pdev)

Actually, the dwc->maximum_speed captures the maximum speed device 
property value. It maybe be set based on the phy's capability if there's 
no property specifying it (i.e. maximum_speed is USB_SPEED_UNKNOWN).

So, this code should be removed. The fix should be in the check of 
dwc3_check_params(). If maximum_speed = USB_SPEED_UNKNOWN and the phy's 
capability is only up to highspeed, then set the maximum_speed to 
highspeed only.

Thanks,
Thinh