Re: [PATCH 1/2] drm/i915/bios: Tolerate devdata==NULL in intel_bios_encoder_supports_dp_dual_mode()

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Tue, Mar 19, 2024 at 11:29:14AM +0200, Jani Nikula wrote:
> On Tue, 19 Mar 2024, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > If we have no VBT, or the VBT didn't declare the encoder
> > in question, we won't have the 'devdata' for the encoder.
> > Instead of oopsing just bail early.
> >
> > We won't be able to tell whether the port is DP++ or not,
> > but so be it.
> >
> > Cc: stable@vger.kernel.org
> > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10464
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_bios.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> > index c7841b3eede8..c13a98431a7b 100644
> > --- a/drivers/gpu/drm/i915/display/intel_bios.c
> > +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> > @@ -3458,6 +3458,9 @@ bool intel_bios_encoder_supports_dp_dual_mode(const struct intel_bios_encoder_da
> >  {
> >  	const struct child_device_config *child = &devdata->child;
> 
> The above oopses already.

Nope. It's just taking the address of the thing.

> 
> BR,
> Jani.
> 
> >  
> > +	if (!devdata)
> > +		return false;
> > +
> >  	if (!intel_bios_encoder_supports_dp(devdata) ||
> >  	    !intel_bios_encoder_supports_hdmi(devdata))
> >  		return false;
> 
> -- 
> Jani Nikula, Intel

-- 
Ville Syrjälä
Intel