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

Thinh Nguyen Thinh.Nguyen at synopsys.com
Thu Jul 23 23:32:31 EDT 2020


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.
>

Are you going into update and resend this patch? If not I can create one 
and add your "Reported-by"

BR,
Thinh


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