[Bug] usb: dwc2: Add functions to set and clear force mode

[John.Youn@xxxxxxxxxxxx (John Youn)]

On 2/2/2016 4:36 PM, Caesar Wang wrote:
> Hi John,
> 
> ? 2016?02?03? 08:03, John Youn ??:
>> On 2/1/2016 6:53 PM, Caesar Wang wrote:
>>> John,
>>>
>>> I will suggest the msleep(25) delay should  put in
>>> 'dwc2_force_dr_mode()' instead of the 'dwc2_clear_force_mode()'
>>>
>> Hi Caesar,
>>
>> Are you saying that just msleep(25) in that function like this solves
>> your issue?
>>
>> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
>> index 39a0fa8..e8a9688 100644
>> --- a/drivers/usb/dwc2/core.c
>> +++ b/drivers/usb/dwc2/core.c
>> @@ -625,6 +625,8 @@ void dwc2_force_dr_mode(struct dwc2_hsotg *hsotg)
>>                           __func__, hsotg->dr_mode);
>>                  break;
>>          }
>> +
>> +       msleep(25);
> 
> Yep, that will solve this issue.
> 

Ok thanks. Though that still seems strange since you should be getting
the msleep(25) from either the dwc2_force_mode() or
dwc2_clear_force_mode().

Can you check if the following patch works?

If so, I think we can go with that to fix the regression for
now. Otherwise I'll just add the extra msleep(25) and revisit this
later.

Regards,
John

---->8----

diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
index e991d55..13c060c 100644
--- a/drivers/usb/dwc2/core.c
+++ b/drivers/usb/dwc2/core.c
@@ -576,7 +576,6 @@ static bool dwc2_force_mode(struct dwc2_hsotg *hsotg, bool host)
        gusbcfg |= set;
        dwc2_writel(gusbcfg, hsotg->regs + GUSBCFG);
 
-       msleep(25);
        return true;
 }
 
@@ -596,7 +595,6 @@ static void dwc2_clear_force_mode(struct dwc2_hsotg *hsotg)
         * NOTE: This long sleep is _very_ important, otherwise the core will
         * not stay in host mode after a connector ID change!
         */
-       msleep(25);
 }
 
 /*
@@ -619,6 +617,8 @@ void dwc2_force_dr_mode(struct dwc2_hsotg *hsotg)
                         __func__, hsotg->dr_mode);
                break;
        }
+
+       msleep(25);
 }