[PATCH] usb: cdns3: gadget: Don't manage pullups

[PATCH] usb: cdns3: gadget: Don't manage pullups

[Roger Quadros]

The USB gadget core is supposed to manage pullups
of the controller. Don't manage pullups from within
the controller driver. Otherwise, function drivers
are not able to keep the controller disconnected from
the bus till they are ready. (e.g. g_webcam)

Signed-off-by: Roger Quadros <rogerq@ti.com>
---
Hi Greg/Felipe,

This can be used for -rc as it is a bug fix.

cheers,
-roger

 drivers/usb/cdns3/gadget.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
index 2ca280f4c054..714382d96055 100644
--- a/drivers/usb/cdns3/gadget.c
+++ b/drivers/usb/cdns3/gadget.c
@@ -2324,8 +2324,6 @@ static void cdns3_gadget_config(struct cdns3_device *priv_dev)
 	writel(USB_CONF_CLK2OFFDS | USB_CONF_L1DS, &regs->usb_conf);
 
 	cdns3_configure_dmult(priv_dev, NULL);
-
-	cdns3_gadget_pullup(&priv_dev->gadget, 1);
 }
 
 /**
@@ -2708,8 +2706,6 @@ static int cdns3_gadget_suspend(struct cdns3 *cdns, bool do_wakeup)
 	/* disable interrupt for device */
 	writel(0, &priv_dev->regs->usb_ien);
 
-	cdns3_gadget_pullup(&priv_dev->gadget, 0);
-
 	return 0;
 }
 
-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

RE: [PATCH] usb: cdns3: gadget: Don't manage pullups

[Pawel Laszczak]

Hi,

Reviewed-by: Pawel Laszczak <pawell@cadence.com>

Regards, 
Pawel, 

>The USB gadget core is supposed to manage pullups
>of the controller. Don't manage pullups from within
>the controller driver. Otherwise, function drivers
>are not able to keep the controller disconnected from
>the bus till they are ready. (e.g. g_webcam)
>
>Signed-off-by: Roger Quadros <rogerq@ti.com>
>---
>Hi Greg/Felipe,
>
>This can be used for -rc as it is a bug fix.
>
>cheers,
>-roger
>
> drivers/usb/cdns3/gadget.c | 4 ----
> 1 file changed, 4 deletions(-)
>
>diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
>index 2ca280f4c054..714382d96055 100644
>--- a/drivers/usb/cdns3/gadget.c
>+++ b/drivers/usb/cdns3/gadget.c
>@@ -2324,8 +2324,6 @@ static void cdns3_gadget_config(struct cdns3_device *priv_dev)
> 	writel(USB_CONF_CLK2OFFDS | USB_CONF_L1DS, &regs->usb_conf);
>
> 	cdns3_configure_dmult(priv_dev, NULL);
>-
>-	cdns3_gadget_pullup(&priv_dev->gadget, 1);
> }
>
> /**
>@@ -2708,8 +2706,6 @@ static int cdns3_gadget_suspend(struct cdns3 *cdns, bool do_wakeup)
> 	/* disable interrupt for device */
> 	writel(0, &priv_dev->regs->usb_ien);
>
>-	cdns3_gadget_pullup(&priv_dev->gadget, 0);
>-
> 	return 0;
> }
>
>--
>Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
>Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH] usb: cdns3: gadget: Don't manage pullups

[Peter Chen]

On 19-10-23 09:17:45, Pawel Laszczak wrote:
> Hi,
> 
> Reviewed-by: Pawel Laszczak <pawell@cadence.com>

Hi Roger & Pawel,

Assume gadget function has already enabled, if you switch host mode
to device mode, with your changes, where the device mode will be enabled
again?

Peter
> 
> Regards, 
> Pawel, 
> 
> >The USB gadget core is supposed to manage pullups
> >of the controller. Don't manage pullups from within
> >the controller driver. Otherwise, function drivers
> >are not able to keep the controller disconnected from
> >the bus till they are ready. (e.g. g_webcam)
> >
> >Signed-off-by: Roger Quadros <rogerq@ti.com>
> >---
> >Hi Greg/Felipe,
> >
> >This can be used for -rc as it is a bug fix.
> >
> >cheers,
> >-roger
> >
> > drivers/usb/cdns3/gadget.c | 4 ----
> > 1 file changed, 4 deletions(-)
> >
> >diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
> >index 2ca280f4c054..714382d96055 100644
> >--- a/drivers/usb/cdns3/gadget.c
> >+++ b/drivers/usb/cdns3/gadget.c
> >@@ -2324,8 +2324,6 @@ static void cdns3_gadget_config(struct cdns3_device *priv_dev)
> > 	writel(USB_CONF_CLK2OFFDS | USB_CONF_L1DS, &regs->usb_conf);
> >
> > 	cdns3_configure_dmult(priv_dev, NULL);
> >-
> >-	cdns3_gadget_pullup(&priv_dev->gadget, 1);
> > }
> >
> > /**
> >@@ -2708,8 +2706,6 @@ static int cdns3_gadget_suspend(struct cdns3 *cdns, bool do_wakeup)
> > 	/* disable interrupt for device */
> > 	writel(0, &priv_dev->regs->usb_ien);
> >
> >-	cdns3_gadget_pullup(&priv_dev->gadget, 0);
> >-
> > 	return 0;
> > }
> >
> >--
> >Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> >Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
> 

-- 

Thanks,
Peter Chen

Re: [PATCH] usb: cdns3: gadget: Don't manage pullups

[Roger Quadros]

Peter,

On 25/10/2019 06:13, Peter Chen wrote:
> On 19-10-23 09:17:45, Pawel Laszczak wrote:
>> Hi,
>>
>> Reviewed-by: Pawel Laszczak <pawell@cadence.com>
> 
> Hi Roger & Pawel,
> 
> Assume gadget function has already enabled, if you switch host mode
> to device mode, with your changes, where the device mode will be enabled
> again?

When it switches from device mode to host the UDC is removed. When we switch
back from host to device mode the UDC is added, so,

usb_add_gadget_udc_release()-> check_pending_gadget_drivers()->
udc_bind_to_driver()->usb_udc_connect_control()->usb_gadget_connect()->
gadget->ops->pullup()

cheers,
-roger
> 
> Peter
>>
>> Regards,
>> Pawel,
>>
>>> The USB gadget core is supposed to manage pullups
>>> of the controller. Don't manage pullups from within
>>> the controller driver. Otherwise, function drivers
>>> are not able to keep the controller disconnected from
>>> the bus till they are ready. (e.g. g_webcam)
>>>
>>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>>> ---
>>> Hi Greg/Felipe,
>>>
>>> This can be used for -rc as it is a bug fix.
>>>
>>> cheers,
>>> -roger
>>>
>>> drivers/usb/cdns3/gadget.c | 4 ----
>>> 1 file changed, 4 deletions(-)
>>>
>>> diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
>>> index 2ca280f4c054..714382d96055 100644
>>> --- a/drivers/usb/cdns3/gadget.c
>>> +++ b/drivers/usb/cdns3/gadget.c
>>> @@ -2324,8 +2324,6 @@ static void cdns3_gadget_config(struct cdns3_device *priv_dev)
>>> 	writel(USB_CONF_CLK2OFFDS | USB_CONF_L1DS, &regs->usb_conf);
>>>
>>> 	cdns3_configure_dmult(priv_dev, NULL);
>>> -
>>> -	cdns3_gadget_pullup(&priv_dev->gadget, 1);
>>> }
>>>
>>> /**
>>> @@ -2708,8 +2706,6 @@ static int cdns3_gadget_suspend(struct cdns3 *cdns, bool do_wakeup)
>>> 	/* disable interrupt for device */
>>> 	writel(0, &priv_dev->regs->usb_ien);
>>>
>>> -	cdns3_gadget_pullup(&priv_dev->gadget, 0);
>>> -
>>> 	return 0;
>>> }
>>>
>>> --
>>> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
>>> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>>
> 

-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH] usb: cdns3: gadget: Don't manage pullups

[Felipe Balbi]

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Hi,

Roger Quadros <rogerq@ti.com> writes:
> On 25/10/2019 06:13, Peter Chen wrote:
>> On 19-10-23 09:17:45, Pawel Laszczak wrote:
>>> Hi,
>>>
>>> Reviewed-by: Pawel Laszczak <pawell@cadence.com>
>> 
>> Hi Roger & Pawel,
>> 
>> Assume gadget function has already enabled, if you switch host mode
>> to device mode, with your changes, where the device mode will be enabled
>> again?
>
> When it switches from device mode to host the UDC is removed. When we switch
> back from host to device mode the UDC is added, so,
>
> usb_add_gadget_udc_release()-> check_pending_gadget_drivers()->
> udc_bind_to_driver()->usb_udc_connect_control()->usb_gadget_connect()->
> gadget->ops->pullup()

I agree with Roger here. UDC shouldn't try to manage pullups
directly. If there are any bugs related to role switch, we should fix it
in udc core, so the fix applies to everyone ;-)

-- 
balbi

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Re: [PATCH] usb: cdns3: gadget: Don't manage pullups

[Peter Chen]

On 19-10-25 12:59:17, Roger Quadros wrote:
> Peter,
> 
> On 25/10/2019 06:13, Peter Chen wrote:
> > On 19-10-23 09:17:45, Pawel Laszczak wrote:
> > > Hi,
> > > 
> > > Reviewed-by: Pawel Laszczak <pawell@cadence.com>
> > 
> > Hi Roger & Pawel,
> > 
> > Assume gadget function has already enabled, if you switch host mode
> > to device mode, with your changes, where the device mode will be enabled
> > again?
> 
> When it switches from device mode to host the UDC is removed. When we switch
> back from host to device mode the UDC is added, so,
> 
> usb_add_gadget_udc_release()-> check_pending_gadget_drivers()->
> udc_bind_to_driver()->usb_udc_connect_control()->usb_gadget_connect()->
> gadget->ops->pullup()

Thanks. I have another question how you decide when to store UDC name
to /sys/kernel/config/usb_gadget/g1/UDC? Do you have a user daemon program
to monitor VBUS or external connector? At host mode, the store operation
will fail due to there is NO UDC.

-- 

Thanks,
Peter Chen

Re: [PATCH] usb: cdns3: gadget: Don't manage pullups

[Roger Quadros]

On 29/10/2019 05:12, Peter Chen wrote:
> On 19-10-25 12:59:17, Roger Quadros wrote:
>> Peter,
>>
>> On 25/10/2019 06:13, Peter Chen wrote:
>>> On 19-10-23 09:17:45, Pawel Laszczak wrote:
>>>> Hi,
>>>>
>>>> Reviewed-by: Pawel Laszczak <pawell@cadence.com>
>>>
>>> Hi Roger & Pawel,
>>>
>>> Assume gadget function has already enabled, if you switch host mode
>>> to device mode, with your changes, where the device mode will be enabled
>>> again?
>>
>> When it switches from device mode to host the UDC is removed. When we switch
>> back from host to device mode the UDC is added, so,
>>
>> usb_add_gadget_udc_release()-> check_pending_gadget_drivers()->
>> udc_bind_to_driver()->usb_udc_connect_control()->usb_gadget_connect()->
>> gadget->ops->pullup()
> 
> Thanks. I have another question how you decide when to store UDC name
> to /sys/kernel/config/usb_gadget/g1/UDC? Do you have a user daemon program
> to monitor VBUS or external connector? At host mode, the store operation
> will fail due to there is NO UDC.
> 

Yes, user space needs to monitor /sys/class/usb_role/6000000.usb-role-switch/role

When it becomes "device" the UDC is available and it can prepare to configure
the UDC.

Could you please give your Ack for this patch if it is OK? Thanks.

cheers,
-roger

-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH] usb: cdns3: gadget: Don't manage pullups

[Felipe Balbi]

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Hi,

Roger Quadros <rogerq@ti.com> writes:

> On 29/10/2019 05:12, Peter Chen wrote:
>> On 19-10-25 12:59:17, Roger Quadros wrote:
>>> Peter,
>>>
>>> On 25/10/2019 06:13, Peter Chen wrote:
>>>> On 19-10-23 09:17:45, Pawel Laszczak wrote:
>>>>> Hi,
>>>>>
>>>>> Reviewed-by: Pawel Laszczak <pawell@cadence.com>
>>>>
>>>> Hi Roger & Pawel,
>>>>
>>>> Assume gadget function has already enabled, if you switch host mode
>>>> to device mode, with your changes, where the device mode will be enabled
>>>> again?
>>>
>>> When it switches from device mode to host the UDC is removed. When we switch
>>> back from host to device mode the UDC is added, so,
>>>
>>> usb_add_gadget_udc_release()-> check_pending_gadget_drivers()->
>>> udc_bind_to_driver()->usb_udc_connect_control()->usb_gadget_connect()->
>>> gadget->ops->pullup()
>> 
>> Thanks. I have another question how you decide when to store UDC name
>> to /sys/kernel/config/usb_gadget/g1/UDC? Do you have a user daemon program
>> to monitor VBUS or external connector? At host mode, the store operation
>> will fail due to there is NO UDC.
>> 
>
> Yes, user space needs to monitor /sys/class/usb_role/6000000.usb-role-switch/role
>
> When it becomes "device" the UDC is available and it can prepare to configure
> the UDC.
>
> Could you please give your Ack for this patch if it is OK? Thanks.

this is already in its way to Linus' tree:

https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/commit/?h=usb-linus&id=f3fb802efaef3662744a2215a51294d52a7cfc0e

-- 
balbi

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Re: [PATCH] usb: cdns3: gadget: Don't manage pullups

[Peter Chen]

On 19-10-29 11:37:31, Roger Quadros wrote:
> 
> 
> On 29/10/2019 05:12, Peter Chen wrote:
> > On 19-10-25 12:59:17, Roger Quadros wrote:
> > > Peter,
> > > 
> > > On 25/10/2019 06:13, Peter Chen wrote:
> > > > On 19-10-23 09:17:45, Pawel Laszczak wrote:
> > > > > Hi,
> > > > > 
> > > > > Reviewed-by: Pawel Laszczak <pawell@cadence.com>
> > > > 
> > > > Hi Roger & Pawel,
> > > > 
> > > > Assume gadget function has already enabled, if you switch host mode
> > > > to device mode, with your changes, where the device mode will be enabled
> > > > again?
> > > 
> > > When it switches from device mode to host the UDC is removed. When we switch
> > > back from host to device mode the UDC is added, so,
> > > 
> > > usb_add_gadget_udc_release()-> check_pending_gadget_drivers()->
> > > udc_bind_to_driver()->usb_udc_connect_control()->usb_gadget_connect()->
> > > gadget->ops->pullup()
> > 
> > Thanks. I have another question how you decide when to store UDC name
> > to /sys/kernel/config/usb_gadget/g1/UDC? Do you have a user daemon program
> > to monitor VBUS or external connector? At host mode, the store operation
> > will fail due to there is NO UDC.
> > 
> 
> Yes, user space needs to monitor /sys/class/usb_role/6000000.usb-role-switch/role
> 
> When it becomes "device" the UDC is available and it can prepare to configure
> the UDC.
> 
> Could you please give your Ack for this patch if it is OK? Thanks.
> 

Acked-by: Peter Chen <peter.chen@nxp.com>

-- 

Thanks,
Peter Chen