[U-Boot] [PATCH v3 4/8] arm: bootm: call udc_disable() before booting linux

Albert ARIBAUD albert.u.boot at aribaud.net
Mon Apr 15 14:56:27 CEST 2013


Hi Tom,

On Mon, 15 Apr 2013 08:45:07 -0400, Tom Rini <trini at ti.com> wrote:

> On Sun, Apr 14, 2013 at 10:12:36PM +0200, Marek Vasut wrote:
> > Dear Albert ARIBAUD,
> > 
> > > Hi Mike,
> > > 
> > > On Fri, 12 Apr 2013 11:59:16 -0700, Mike Dunn <mikedunn at newsguy.com>
> > > 
> > > wrote:
> > > > On the pxa270, if the udc device is not disabled before jumping to linux,
> > > > the device fails to initialize in linux because it was left in a running
> > > > state, and the linux driver assumes that it is in a disabled state.
> > > > 
> > > > Signed-off-by: Mike Dunn <mikedunn at newsguy.com>
> > > > ---
> > > > 
> > > > Changelog:
> > > >   v3: no change
> > > >   v2: no change
> > > > 
> > > > Arguably, this is a bug in the linux driver, but it seemed pretty simple
> > > > and benign to just disable it in u-boot.  I'll also send a patch to
> > > > upstream kernel to fix its driver.
> > > > 
> > > >  arch/arm/include/asm/bootm.h |    1 +
> > > >  arch/arm/lib/bootm.c         |    1 +
> > > >  2 files changed, 2 insertions(+), 0 deletions(-)
> > > > 
> > > > diff --git a/arch/arm/include/asm/bootm.h b/arch/arm/include/asm/bootm.h
> > > > index db2ff94..68189cc 100644
> > > > --- a/arch/arm/include/asm/bootm.h
> > > > +++ b/arch/arm/include/asm/bootm.h
> > > > @@ -21,6 +21,7 @@
> > > > 
> > > >  #ifdef CONFIG_USB_DEVICE
> > > >  extern void udc_disconnect(void);
> > > > 
> > > > +extern void udc_disable(void);
> > > > 
> > > >  #endif
> > > >  
> > > >  #endif
> > > > 
> > > > diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
> > > > index f3b30c5..6daa7bf 100644
> > > > --- a/arch/arm/lib/bootm.c
> > > > +++ b/arch/arm/lib/bootm.c
> > > > @@ -105,6 +105,7 @@ static void announce_and_cleanup(void)
> > > > 
> > > >  #ifdef CONFIG_USB_DEVICE
> > > >  
> > > >  	udc_disconnect();
> > > > 
> > > > +	udc_disable();
> > > > 
> > > >  #endif
> > > >  
> > > >  	cleanup_before_linux();
> > > >  
> > > >  }
> > > 
> > > Acked-By: Albert ARIBAUD <albert.u.boot at aribaud.net>
> > 
> > Tom, will this not break any of your musb-toys?
> 
> Albert, did you test this on your musb using nearly released now board?
> :)

No, I haven't. I had assumed from Marex' request that this worked for
him and he wanted my formal ack on it.

Amicalement,
-- 
Albert.


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