2019-04-04 09:40:13

by Paul Cercueil

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Subject: [PATCH] usb: musb: Disable pullup in gadget setup

The pullup may be already enabled before the driver is initialized.
It has to be disabled at init time, as we cannot guarantee that a gadget
driver will be bound to the UDC.

Signed-off-by: Paul Cercueil <[email protected]>
---
drivers/usb/musb/musb_gadget.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index ffe462a657b1..094dc59c834c 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -1794,6 +1794,7 @@ int musb_gadget_setup(struct musb *musb)

musb->is_active = 0;
musb_platform_try_idle(musb, 0);
+ musb_pullup(musb, 0);

status = usb_add_gadget_udc(musb->controller, &musb->g);
if (status)
--
2.11.0


2019-04-04 16:11:55

by Bin Liu

[permalink] [raw]
Subject: Re: [PATCH] usb: musb: Disable pullup in gadget setup

On Thu, Apr 04, 2019 at 11:37:43AM +0200, Paul Cercueil wrote:
> The pullup may be already enabled before the driver is initialized.
> It has to be disabled at init time, as we cannot guarantee that a gadget
> driver will be bound to the UDC.
>
> Signed-off-by: Paul Cercueil <[email protected]>
> ---
> drivers/usb/musb/musb_gadget.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
> index ffe462a657b1..094dc59c834c 100644
> --- a/drivers/usb/musb/musb_gadget.c
> +++ b/drivers/usb/musb/musb_gadget.c
> @@ -1794,6 +1794,7 @@ int musb_gadget_setup(struct musb *musb)
>
> musb->is_active = 0;
> musb_platform_try_idle(musb, 0);
> + musb_pullup(musb, 0);
>
> status = usb_add_gadget_udc(musb->controller, &musb->g);
> if (status)

Applied.

Thanks,
-Bin.

2019-04-30 15:06:54

by Bin Liu

[permalink] [raw]
Subject: Re: [PATCH] usb: musb: Disable pullup in gadget setup

Hi Paul,

On Thu, Apr 04, 2019 at 11:10:46AM -0500, Bin Liu wrote:
> On Thu, Apr 04, 2019 at 11:37:43AM +0200, Paul Cercueil wrote:
> > The pullup may be already enabled before the driver is initialized.
> > It has to be disabled at init time, as we cannot guarantee that a gadget
> > driver will be bound to the UDC.
> >
> > Signed-off-by: Paul Cercueil <[email protected]>
> > ---
> > drivers/usb/musb/musb_gadget.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
> > index ffe462a657b1..094dc59c834c 100644
> > --- a/drivers/usb/musb/musb_gadget.c
> > +++ b/drivers/usb/musb/musb_gadget.c
> > @@ -1794,6 +1794,7 @@ int musb_gadget_setup(struct musb *musb)
> >
> > musb->is_active = 0;
> > musb_platform_try_idle(musb, 0);
> > + musb_pullup(musb, 0);
> >
> > status = usb_add_gadget_udc(musb->controller, &musb->g);
> > if (status)
>
> Applied.

Sorry, I have dropped this patch from my tree. I realized the gadget
core already defines callbacks to control the pullup. I think the
proper fix should be calling usb_udc_vbus_handler() in musb gadget or
glue layers.

-Bin.

2019-04-30 15:13:40

by Bin Liu

[permalink] [raw]
Subject: Re: [PATCH] usb: musb: Disable pullup in gadget setup

On Tue, Apr 30, 2019 at 10:05:06AM -0500, Bin Liu wrote:
> Hi Paul,
>
> On Thu, Apr 04, 2019 at 11:10:46AM -0500, Bin Liu wrote:
> > On Thu, Apr 04, 2019 at 11:37:43AM +0200, Paul Cercueil wrote:
> > > The pullup may be already enabled before the driver is initialized.
> > > It has to be disabled at init time, as we cannot guarantee that a gadget
> > > driver will be bound to the UDC.
> > >
> > > Signed-off-by: Paul Cercueil <[email protected]>
> > > ---
> > > drivers/usb/musb/musb_gadget.c | 1 +
> > > 1 file changed, 1 insertion(+)
> > >
> > > diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
> > > index ffe462a657b1..094dc59c834c 100644
> > > --- a/drivers/usb/musb/musb_gadget.c
> > > +++ b/drivers/usb/musb/musb_gadget.c
> > > @@ -1794,6 +1794,7 @@ int musb_gadget_setup(struct musb *musb)
> > >
> > > musb->is_active = 0;
> > > musb_platform_try_idle(musb, 0);
> > > + musb_pullup(musb, 0);
> > >
> > > status = usb_add_gadget_udc(musb->controller, &musb->g);
> > > if (status)
> >
> > Applied.
>
> Sorry, I have dropped this patch from my tree. I realized the gadget
> core already defines callbacks to control the pullup. I think the
> proper fix should be calling usb_udc_vbus_handler() in musb gadget or
> glue layers.

Basically besides the problem your patch tries to fix, there is another
problem related to the pullup, which is enabled right after bind a
gadget driver, regardless of vbus status. This violates the USB Spec.
Implementing the udc core callbacks should fix both issues.

-Bin.

2019-07-15 06:07:27

by Paul Cercueil

[permalink] [raw]
Subject: Re: [PATCH] usb: musb: Disable pullup in gadget setup

Hi Bin,


Le mar. 30 avril 2019 ? 11:05, Bin Liu <[email protected]> a ?crit :
> Hi Paul,
>
> On Thu, Apr 04, 2019 at 11:10:46AM -0500, Bin Liu wrote:
>> On Thu, Apr 04, 2019 at 11:37:43AM +0200, Paul Cercueil wrote:
>> > The pullup may be already enabled before the driver is
>> initialized.
>> > It has to be disabled at init time, as we cannot guarantee that a
>> gadget
>> > driver will be bound to the UDC.
>> >
>> > Signed-off-by: Paul Cercueil <[email protected]>
>> > ---
>> > drivers/usb/musb/musb_gadget.c | 1 +
>> > 1 file changed, 1 insertion(+)
>> >
>> > diff --git a/drivers/usb/musb/musb_gadget.c
>> b/drivers/usb/musb/musb_gadget.c
>> > index ffe462a657b1..094dc59c834c 100644
>> > --- a/drivers/usb/musb/musb_gadget.c
>> > +++ b/drivers/usb/musb/musb_gadget.c
>> > @@ -1794,6 +1794,7 @@ int musb_gadget_setup(struct musb *musb)
>> >
>> > musb->is_active = 0;
>> > musb_platform_try_idle(musb, 0);
>> > + musb_pullup(musb, 0);
>> >
>> > status = usb_add_gadget_udc(musb->controller, &musb->g);
>> > if (status)
>>
>> Applied.
>
> Sorry, I have dropped this patch from my tree. I realized the gadget
> core already defines callbacks to control the pullup. I think the
> proper fix should be calling usb_udc_vbus_handler() in musb gadget or
> glue layers.
>
> -Bin.

usb_udc_vbus_handler() requires a usb_gadget *, I don't see where I can
get that from the struct musb.

Besides, the point is to have the pullup disabled before a gadget is
bound,
so I don't understand why you suggest that?

-Paul