* usb: musb: Disable pullup in gadget setup
@ 2019-04-30 15:05 ` Bin Liu
0 siblings, 0 replies; 9+ messages in thread
From: Bin Liu @ 2019-04-30 15:05 UTC (permalink / raw)
To: Paul Cercueil, od, linux-usb, linux-kernel
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 <paul@crapouillou.net>
> > ---
> > 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.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] usb: musb: Disable pullup in gadget setup
@ 2019-04-30 15:10 ` Bin Liu
0 siblings, 0 replies; 9+ messages in thread
From: Bin Liu @ 2019-04-30 15:10 UTC (permalink / raw)
To: Paul Cercueil, od, linux-usb, linux-kernel
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 <paul@crapouillou.net>
> > > ---
> > > 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.
^ permalink raw reply [flat|nested] 9+ messages in thread
* usb: musb: Disable pullup in gadget setup
@ 2019-04-30 15:10 ` Bin Liu
0 siblings, 0 replies; 9+ messages in thread
From: Bin Liu @ 2019-04-30 15:10 UTC (permalink / raw)
To: Paul Cercueil, od, linux-usb, linux-kernel
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 <paul@crapouillou.net>
> > > ---
> > > 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.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] usb: musb: Disable pullup in gadget setup
2019-04-30 15:05 ` Bin Liu
(?)
(?)
@ 2019-07-15 6:05 ` Paul Cercueil
-1 siblings, 0 replies; 9+ messages in thread
From: Paul Cercueil @ 2019-07-15 6:05 UTC (permalink / raw)
To: Bin Liu; +Cc: od, linux-usb, linux-kernel
Hi Bin,
Le mar. 30 avril 2019 à 11:05, Bin Liu <b-liu@ti.com> a écrit :
> 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 <paul@crapouillou.net>
>> > ---
>> > 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
^ permalink raw reply [flat|nested] 9+ messages in thread