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

[Caesar Wang]

John,

I will suggest the msleep(25) delay should  put in 
'dwc2_force_dr_mode()' instead of the 'dwc2_clear_force_mode()'

在 2016年02月02日 10:42, Caesar Wang 写道:
> Hi John,
>
> 在 2016年02月02日 07:31, John Youn 写道:
>> On 2/1/2016 3:13 AM, Caesar Wang wrote:
>>>
>>> 在 2016年02月01日 19:12, Caesar Wang 写道:
>>>> Doug
>>>>
>>>> 在 2016年01月30日 03:11, Doug Anderson 写道:
>>>>> Caesar,
>>>>>
>>>>> On Tue, Jan 26, 2016 at 6:12 PM, Caesar Wang
>>>>> <caesar.upstream at gmail.com> wrote:
>>>>>> Thanks Doug's reply.
>>>>>>
>>>>>> Cc: Wulf
>>>>>> 在 2016年01月27日 00:05, Doug Anderson 写道:
>>>>>>> Hi,
>>>>>>>
>>>>>>> On Tue, Jan 26, 2016 at 4:02 AM, Caesar Wang <wxt at rock-chips.com>
>>>>>>> wrote:
>>>>>>>> Hi  John, Felipe
>>>>>>>>
>>>>>>>>
>>>>>>>> I'm no familiar with usb stuff.
>>>>>>>> then I found this patch will break usb working for rk3036 SoCs, 
>>>>>>>> maybe
>>>>>>>> more
>>>>>>>> SoCs.
>>>>>>>> Says, U disk can't work on usb host.
>>>>>>>>
>>>>>>>> The failure log:
>>>>>>>>
>>>>>>>>       32.645481] usb usb2-port1: connect-debounce failed
>>>>>>>>
>>>>>>>>
>>>>>>>> Tested by following branch:
>>>>>>>> https://github.com/Caesar-github/rockchip/tree/kylin/next (kernel:
>>>>>>>> 4.5-rc1)
>>>>>>>>
>>>>>>>> Revert "usb: dwc2: Add functions to set and clear force mode" will
>>>>>>>> work
>>>>>>>> for
>>>>>>>> it.
>>>>>>>>
>>>>>>>>
>>>>>>>> Maybe, someone have some suggestions or ideas?
>>>>>>> Can you check if this series helps you?
>>>>>>>
>>>>>>> http://marc.info/?l=linux-usb&m=145255851516121&w=2
>>>>>> Unluckily, this series patches can't fix it on rk3036 SoCs.
>>>>>> I revert this CL ("usb: dwc2: Add functions to set and clear force
>>>>>> mode") to
>>>>>> work firstly.
>>>>> You're 100% positive?  In particular you made sure you had this patch
>>>>> (one of the two in John's series I pointed at), which explicitly
>>>>> mentions fixing a problem with the patch you mention?
>>>> I'm 100% positive the John's patches can fix this issue
>>> Sorry, John's patches can't fix this issue.
>>>
>>>
>>>> As the following verified on
>>>> https://github.com/Caesar-github/rockchip/commits/for-usb-tests
>>>>
>>>> Anyway, Meanwhile if we add the folllowing patch can work for me. I
>>>> will track it on tomorrow if you have other suggestions.
>>>>
>>>> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
>>>>
>>>> index e991d55..90f4abf 100644
>>>>
>>>> --- a/drivers/usb/dwc2/core.c
>>>>
>>>> +++ b/drivers/usb/dwc2/core.c
>>>>
>>>> @@ -637,6 +637,13 @@ int dwc2_core_reset_and_force_dr_mode(struct
>>>> dwc2_hsotg *hsotg)
>>>>
>>>>                  return retval;
>>>>
>>>>
>>>>
>>>>          dwc2_force_dr_mode(hsotg);
>>>>
>>>> +
>>>>
>>>> +       /*
>>>>
>>>> +        * NOTE: This long sleep is_very_  important, otherwise the 
>>>> core
>>>> will
>>>>
>>>> +        * not stay in host mode after a connector ID change!
>>>>
>>>> +        */
>>>>
>>>> +        usleep_range(150000, 160000);
>>>>
>>>> +
>>>>
>>>>          return 0;
>>>>
>>>>   }
>>>>
>> Hi Cesar,
>>
>> On your platform, is the dwc2 controller OTG? If so, what mode is the
>> driver running in (dr_mode=HOST, PERIPHERAL, or OTG)?
>
>
> It's the Host mode. ( USB_DR_MODE_HOST)
>
>>
>> The force mode only requires 25ms delay but maybe the sleep needs to
>> be longer on your system for some other reason. Which is unfortunate
>> because 150ms is very long.
>>
>> Under what condition do you see the problem. Is it on connector ID
>> change? If so we might put the long delay in a more appropriate
>> location so as not to affect delay in probe.
>>
>> Also, could you try *only* reverting the following:
>>
>> commit 97e463886b873f62bea2293e7edf81fdb884b84f ("usb: dwc2: Reduce
>> delay when forcing mode in reset")
>
> I'm sure can't work if we revert it.
> log
> ...:
> "[    5.705971] usb usb2-port1: connect-debounce failed"
>
> d4b3ff1 Revert "usb: dwc2: Reduce delay when forcing mode in reset"
> c69654f usb: dwc2: Fix probe problem on bcm283
> b9da0ff Revert "usb: dwc2: Move reset into dwc2_get_hwparams()
>
> -- 
>
> Then, add the following patch can work.
>
> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
> index e991d55..90f4abf 100644
> --- a/drivers/usb/dwc2/core.c
> +++ b/drivers/usb/dwc2/core.c
> @@ -637,6 +637,13 @@ int dwc2_core_reset_and_force_dr_mode(struct 
> dwc2_hsotg *hsotg)
>                 return retval;
>
>         dwc2_force_dr_mode(hsotg);
> +
> +       /*
> +        * NOTE: This long sleep is _very_ important, otherwise the 
> core will
> +        * not stay in host mode after a connector ID change!
> +        */
> +        usleep_range(150000, 160000);
> +
>         return 0;
>  }
>
>> The original patch you referred to preserves the long delay at the
>> point it is used for OTG but then this later patch (97e46388)
>> decreased the value. So maybe we can just revert this later patch.
>>
>> Regards,
>> John
>> _______________________________________________
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>> Linux-rockchip at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-rockchip
>
>
>

-- 
Thanks,
Caesar