[Intel-gfx] [PATCH] drm/i915/display: Set error value before returning in intel_hdcp*_disable()

[Gupta, Anshuman]

> -----Original Message-----
> From: Gupta, Anshuman
> Sent: Friday, January 15, 2021 5:39 PM
> To: 'Jani Nikula' <jani.nikula at intel.com>; Chris Wilson <chris at chris-
> wilson.co.uk>; intel-gfx at lists.freedesktop.org
> Cc: Chris Wilson <chris at chris-wilson.co.uk>; C, Ramalingam
> <ramalingam.c at intel.com>; Shankar, Uma <uma.shankar at intel.com>;
> Sean Paul <seanpaul at chromium.org>
> Subject: RE: [PATCH] drm/i915/display: Set error value before returning in
> intel_hdcp*_disable()
> 
> 
> 
> > -----Original Message-----
> > From: Jani Nikula <jani.nikula at intel.com>
> > Sent: Friday, January 15, 2021 4:05 PM
> > To: Chris Wilson <chris at chris-wilson.co.uk>;
> > intel-gfx at lists.freedesktop.org
> > Cc: Chris Wilson <chris at chris-wilson.co.uk>; C, Ramalingam
> > <ramalingam.c at intel.com>; Shankar, Uma <uma.shankar at intel.com>;
> Gupta,
> > Anshuman <anshuman.gupta at intel.com>; Sean Paul
> <seanpaul at chromium.org>
> > Subject: Re: [PATCH] drm/i915/display: Set error value before
> > returning in
> > intel_hdcp*_disable()
> >
> > On Fri, 15 Jan 2021, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> > > drivers/gpu/drm/i915/display/intel_hdcp.c:886 _intel_hdcp_disable()
> > error: uninitialized symbol 'ret'.
> > > drivers/gpu/drm/i915/display/intel_hdcp.c:1951
> > > _intel_hdcp2_disable()
> > error: uninitialized symbol 'ret'.
> > >
> > > Given the comment that this error reflects the status of all
> > > connectors within this MST topology, I opted to use -EBUSY to
> > > indicate not all were ready.
> > >
> > > Fixes: 2a743b7b8a8b ("drm/i915/hdcp: Configure HDCP1.4 MST steram
> > > encryption status")
> > > Fixes: 899c8762f981 ("drm/i915/hdcp: Configure HDCP2.2 MST steram
> > > encryption status")
> > > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > > Cc: Ramalingam C <ramalingam.c at intel.com>
> > > Cc: Uma Shankar <uma.shankar at intel.com>
> > > Cc: Anshuman Gupta <anshuman.gupta at intel.com>
> > > Cc: Sean Paul <seanpaul at chromium.org>
> > > Cc: Jani Nikula <jani.nikula at intel.com>
> >
> > Reviewed-by: Jani Nikula <jani.nikula at intel.com>
> >
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_hdcp.c | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > index db8dff2eeb0a..2be4822b91a0 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > @@ -883,7 +883,7 @@ static int _intel_hdcp_disable(struct
> > intel_connector *connector)
> > >  	 * until it disabled HDCP encryption for all connectors in MST
> > topology.
> > >  	 */
> > >  	if (dig_port->num_hdcp_streams > 0)
> > > -		return ret;
> > > +		return -EBUSY;
> Please return 0  as a fix to static analysis warning, It is not an error.
> Above condition will only true for MST case, so it always was returning
> return value from stream_encryption().
> 
> Thanks,
> Anshuman Gupta.
Floated a patch to fix this https://patchwork.freedesktop.org/patch/414427/?series=85917&rev=1

Thanks,
Anshuman Gupta.
> > >
> > >  	hdcp->hdcp_encrypted = false;
> > >  	intel_de_write(dev_priv, HDCP_CONF(dev_priv, cpu_transcoder,
> > port),
> > > 0); @@ -1948,7 +1948,7 @@ static int _intel_hdcp2_disable(struct
> > intel_connector *connector)
> > >  	}
> > >
> > >  	if (dig_port->num_hdcp_streams > 0)
> > > -		return ret;
> > > +		return -EBUSY;
> > >
> > >  	ret = hdcp2_disable_encryption(connector);
> >
> > --
> > Jani Nikula, Intel Open Source Graphics Center