[RFC PATCH] usb: dwc3: fix maximum_speed check for usb2.0-only core

[Chunfeng Yun]

On Fri, 2020-07-24 at 03:32 +0000, Thinh Nguyen wrote:
> Hi,
> 
> Thinh Nguyen wrote:
> > 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 at mediatek.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.
Sorry for the late reply, my outlook lose your email.
> >
> 
> Are you going into update and resend this patch?
I don't know how to check "the phy's capability is only up to highspeed"

>  If not I can create one 
> and add your "Reported-by"
Ok, thanks

> 
> BR,
> Thinh