Re: [PATCH 2/15] usb: typec: Add parameter for the VDO to typec_altmode_enter()

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

Hi Andy,

> Sun, Jan 25, 2026 at 11:54:22AM +0800, Andy Yan wrote:
> > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> > > index 56fc356bc55c..f3087ef8265c 100644
> > > --- a/drivers/usb/typec/tcpm/tcpm.c
> > > +++ b/drivers/usb/typec/tcpm/tcpm.c
> > > @@ -1475,16 +1475,16 @@ static int tcpm_validate_caps(struct tcpm_port *port, const u32 *pdo,
> > >  	return 0;
> > >  }
> > >  
> > > -static int tcpm_altmode_enter(struct typec_altmode *altmode)
> > > +static int tcpm_altmode_enter(struct typec_altmode *altmode, u32 *vdo)
> > >  {
> > >  	struct tcpm_port *port = typec_altmode_get_drvdata(altmode);
> > >  	u32 header;
> > >  
> > >  	mutex_lock(&port->lock);
> > > -	header = VDO(altmode->svid, 1, CMD_ENTER_MODE);
> > > +	header = VDO(altmode->svid, vdo ? 2 : 1, CMD_ENTER_MODE);
> > >  	header |= VDO_OPOS(altmode->mode);
> > 
> > Sorry to bother you. I happened to come across this piece of code and
> > I'm not quite clear about this part: vdo ? 2 : 1
> > 
> > According to the definition of the VDO macro(pd_vdo.h), the type here is
> > only 1 bit wide, located at bit 15. If the type value is set to 2 here,
> > wouldn’t that overwrite bit 16?
> 
> That looks like just an obvious bug to me.

Whoa, the thread and patch seem to be really old.

Please just prepare the fix. Let's discuss it there if there's
anything.

thanks,

-- 
heikki