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

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

[Ville Syrjala]

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;
 
+	if (!devdata)
+		return false;
+
 	if (!intel_bios_encoder_supports_dp(devdata) ||
 	    !intel_bios_encoder_supports_hdmi(devdata))
 		return false;
-- 
2.43.2

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

[Jani Nikula]

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.

BR,
Jani.

>  
> +	if (!devdata)
> +		return false;
> +
>  	if (!intel_bios_encoder_supports_dp(devdata) ||
>  	    !intel_bios_encoder_supports_hdmi(devdata))
>  		return false;

-- 
Jani Nikula, Intel

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

[Ville Syrjälä]

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

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

[Jani Nikula]

On Tue, 19 Mar 2024, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> 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.

I guess. Still looks a bit suspicious. :/

Reviewed-by: Jani Nikula <jani.nikula@intel.com>


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

-- 
Jani Nikula, Intel