Re: [PATCH v3 5/7] drm: Validate encoder->possible_clones
On Tue, Feb 11, 2020 at 07:13:31PM +0200, Ville Syrjälä wrote: > On Tue, Feb 11, 2020 at 06:02:33PM +0100, Daniel Vetter wrote: > > On Tue, Feb 11, 2020 at 06:22:06PM +0200, Ville Syrjala wrote: > > > From: Ville Syrjälä > > > > > > Many drivers are populating encoder->possible_clones wrong. Let's > > > persuade them to get it right by adding some loud WARNs. > > > > > > We'll cross check the bits between any two encoders. So either > > > both encoders can clone with the other, or neither can. > > > > > > We'll also complain about effectively empty possible_clones, and > > > possible_clones containing bits for encoders that don't exist. > > > > > > v2: encoder->possible_clones now includes the encoder itelf > > > v3: Move to drm_mode_config_validate() (Daniel) > > > Document that you get a WARN when this is wrong (Daniel) > > > Extract full_encoder_mask() > > > > > > Acked-by: Thomas Zimmermann > > > Cc: Daniel Vetter > > > Signed-off-by: Ville Syrjälä > > > > I wonder whether we should start to have some unit tests for stuff like > > this, like set up broken driver, make sure we have a WARN in dmesg. But > > ideally we'd do that with the mocking stuff Kunit hopefully has soon. > > > > > > > > > > > --- > > > drivers/gpu/drm/drm_mode_config.c | 40 +++ > > > include/drm/drm_encoder.h | 2 ++ > > > 2 files changed, 42 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/drm_mode_config.c > > > b/drivers/gpu/drm/drm_mode_config.c > > > index 75e357c7e84d..afc91447293a 100644 > > > --- a/drivers/gpu/drm/drm_mode_config.c > > > +++ b/drivers/gpu/drm/drm_mode_config.c > > > @@ -533,6 +533,17 @@ void drm_mode_config_cleanup(struct drm_device *dev) > > > } > > > EXPORT_SYMBOL(drm_mode_config_cleanup); > > > > > > +static u32 full_encoder_mask(struct drm_device *dev) > > > +{ > > > + struct drm_encoder *encoder; > > > + u32 encoder_mask = 0; > > > + > > > + drm_for_each_encoder(encoder, dev) > > > + encoder_mask |= drm_encoder_mask(encoder); > > > + > > > + return encoder_mask; > > > +} > > > + > > > /* > > > * For some reason we want the encoder itself included in > > > * possible_clones. Make life easy for drivers by allowing them > > > @@ -544,10 +555,39 @@ static void fixup_encoder_possible_clones(struct > > > drm_encoder *encoder) > > > encoder->possible_clones = drm_encoder_mask(encoder); > > > } > > > > > > +static void validate_encoder_possible_clones(struct drm_encoder *encoder) > > > +{ > > > + struct drm_device *dev = encoder->dev; > > > + u32 encoder_mask = full_encoder_mask(dev); > > > + struct drm_encoder *other; > > > + > > > + drm_for_each_encoder(other, dev) { > > > + WARN(!(encoder->possible_clones & drm_encoder_mask(other)) != > > > + !(other->possible_clones & drm_encoder_mask(encoder)), > > > > Bikeshed: !! as canonical "make this a bool value" might be slightly > > clearer, but whatever. > > Can repaint. > > > > > > + "possible_clones mismatch: " > > > + "[ENCODER:%d:%s] mask=0x%x possible_clones=0x%x vs. " > > > + "[ENCODER:%d:%s] mask=0x%x possible_clones=0x%x\n", > > > + encoder->base.id, encoder->name, > > > + drm_encoder_mask(encoder), encoder->possible_clones, > > > + other->base.id, other->name, > > > + drm_encoder_mask(other), other->possible_clones); > > > + } > > > + > > > + WARN((encoder->possible_clones & drm_encoder_mask(encoder)) == 0 || > > > + (encoder->possible_clones & ~encoder_mask) != 0, > > > + "Bogus possible_clones: " > > > + "[ENCODER:%d:%s] possible_clones=0x%x (full encoder mask=0x%x)\n", > > > + encoder->base.id, encoder->name, > > > + encoder->possible_clones, encoder_mask); > > > +} > > > > Since it's next to each another double-checking that the fixup did add the > > self-clone is probably too much :-) > > I changed the fixup to be just > if (possible_clones == 0) > possible_clones = drm_encoder_mask(); > > So if the driver tries to set it up but fails and forgets the > encoder itself this WARN will still trip. Duh, I was just blind, everything is looking good. -Daniel > > > > > > + > > > void drm_mode_config_validate(struct drm_device *dev) > > > { > > > struct drm_encoder *encoder; > > > > > > drm_for_each_encoder(encoder, dev) > > > fixup_encoder_possible_clones(encoder); > > > + > > > + drm_for_each_encoder(encoder, dev) > > > + validate_encoder_possible_clones(encoder); > > > > > } > > > diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h > > > index 22d6cdf729f1..3741963b9587 100644 > > > --- a/include/drm/drm_encoder.h > > > +++ b/include/drm/drm_encoder.h > > > @@ -163,6 +163,8 @@ struct drm_encoder { > > >* any cloning it can leave @possible_clones set to 0. The core will > > >* automagically fix this up by setting the bit for the encoder itself. > > >* >
Re: [PATCH v3 5/7] drm: Validate encoder->possible_clones
On Tue, Feb 11, 2020 at 06:02:33PM +0100, Daniel Vetter wrote: > On Tue, Feb 11, 2020 at 06:22:06PM +0200, Ville Syrjala wrote: > > From: Ville Syrjälä > > > > Many drivers are populating encoder->possible_clones wrong. Let's > > persuade them to get it right by adding some loud WARNs. > > > > We'll cross check the bits between any two encoders. So either > > both encoders can clone with the other, or neither can. > > > > We'll also complain about effectively empty possible_clones, and > > possible_clones containing bits for encoders that don't exist. > > > > v2: encoder->possible_clones now includes the encoder itelf > > v3: Move to drm_mode_config_validate() (Daniel) > > Document that you get a WARN when this is wrong (Daniel) > > Extract full_encoder_mask() > > > > Acked-by: Thomas Zimmermann > > Cc: Daniel Vetter > > Signed-off-by: Ville Syrjälä > > I wonder whether we should start to have some unit tests for stuff like > this, like set up broken driver, make sure we have a WARN in dmesg. But > ideally we'd do that with the mocking stuff Kunit hopefully has soon. > > > > > > --- > > drivers/gpu/drm/drm_mode_config.c | 40 +++ > > include/drm/drm_encoder.h | 2 ++ > > 2 files changed, 42 insertions(+) > > > > diff --git a/drivers/gpu/drm/drm_mode_config.c > > b/drivers/gpu/drm/drm_mode_config.c > > index 75e357c7e84d..afc91447293a 100644 > > --- a/drivers/gpu/drm/drm_mode_config.c > > +++ b/drivers/gpu/drm/drm_mode_config.c > > @@ -533,6 +533,17 @@ void drm_mode_config_cleanup(struct drm_device *dev) > > } > > EXPORT_SYMBOL(drm_mode_config_cleanup); > > > > +static u32 full_encoder_mask(struct drm_device *dev) > > +{ > > + struct drm_encoder *encoder; > > + u32 encoder_mask = 0; > > + > > + drm_for_each_encoder(encoder, dev) > > + encoder_mask |= drm_encoder_mask(encoder); > > + > > + return encoder_mask; > > +} > > + > > /* > > * For some reason we want the encoder itself included in > > * possible_clones. Make life easy for drivers by allowing them > > @@ -544,10 +555,39 @@ static void fixup_encoder_possible_clones(struct > > drm_encoder *encoder) > > encoder->possible_clones = drm_encoder_mask(encoder); > > } > > > > +static void validate_encoder_possible_clones(struct drm_encoder *encoder) > > +{ > > + struct drm_device *dev = encoder->dev; > > + u32 encoder_mask = full_encoder_mask(dev); > > + struct drm_encoder *other; > > + > > + drm_for_each_encoder(other, dev) { > > + WARN(!(encoder->possible_clones & drm_encoder_mask(other)) != > > +!(other->possible_clones & drm_encoder_mask(encoder)), > > Bikeshed: !! as canonical "make this a bool value" might be slightly > clearer, but whatever. Can repaint. > > > +"possible_clones mismatch: " > > +"[ENCODER:%d:%s] mask=0x%x possible_clones=0x%x vs. " > > +"[ENCODER:%d:%s] mask=0x%x possible_clones=0x%x\n", > > +encoder->base.id, encoder->name, > > +drm_encoder_mask(encoder), encoder->possible_clones, > > +other->base.id, other->name, > > +drm_encoder_mask(other), other->possible_clones); > > + } > > + > > + WARN((encoder->possible_clones & drm_encoder_mask(encoder)) == 0 || > > +(encoder->possible_clones & ~encoder_mask) != 0, > > +"Bogus possible_clones: " > > +"[ENCODER:%d:%s] possible_clones=0x%x (full encoder mask=0x%x)\n", > > +encoder->base.id, encoder->name, > > +encoder->possible_clones, encoder_mask); > > +} > > Since it's next to each another double-checking that the fixup did add the > self-clone is probably too much :-) I changed the fixup to be just if (possible_clones == 0) possible_clones = drm_encoder_mask(); So if the driver tries to set it up but fails and forgets the encoder itself this WARN will still trip. > > > + > > void drm_mode_config_validate(struct drm_device *dev) > > { > > struct drm_encoder *encoder; > > > > drm_for_each_encoder(encoder, dev) > > fixup_encoder_possible_clones(encoder); > > + > > + drm_for_each_encoder(encoder, dev) > > + validate_encoder_possible_clones(encoder); > > > } > > diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h > > index 22d6cdf729f1..3741963b9587 100644 > > --- a/include/drm/drm_encoder.h > > +++ b/include/drm/drm_encoder.h > > @@ -163,6 +163,8 @@ struct drm_encoder { > > * any cloning it can leave @possible_clones set to 0. The core will > > * automagically fix this up by setting the bit for the encoder itself. > > * > > +* You will get a WARN if you get this wrong in the driver. > > Nice. > > Reviewed-by: Daniel Vetter > > > +* > > * Note that since encoder objects can't be hotplugged the assigned > > indices > > * are stable and hence known before registering all objects. > > */ > > -- >
Re: [PATCH v3 5/7] drm: Validate encoder->possible_clones
On Tue, Feb 11, 2020 at 06:22:06PM +0200, Ville Syrjala wrote: > From: Ville Syrjälä > > Many drivers are populating encoder->possible_clones wrong. Let's > persuade them to get it right by adding some loud WARNs. > > We'll cross check the bits between any two encoders. So either > both encoders can clone with the other, or neither can. > > We'll also complain about effectively empty possible_clones, and > possible_clones containing bits for encoders that don't exist. > > v2: encoder->possible_clones now includes the encoder itelf > v3: Move to drm_mode_config_validate() (Daniel) > Document that you get a WARN when this is wrong (Daniel) > Extract full_encoder_mask() > > Acked-by: Thomas Zimmermann > Cc: Daniel Vetter > Signed-off-by: Ville Syrjälä I wonder whether we should start to have some unit tests for stuff like this, like set up broken driver, make sure we have a WARN in dmesg. But ideally we'd do that with the mocking stuff Kunit hopefully has soon. > --- > drivers/gpu/drm/drm_mode_config.c | 40 +++ > include/drm/drm_encoder.h | 2 ++ > 2 files changed, 42 insertions(+) > > diff --git a/drivers/gpu/drm/drm_mode_config.c > b/drivers/gpu/drm/drm_mode_config.c > index 75e357c7e84d..afc91447293a 100644 > --- a/drivers/gpu/drm/drm_mode_config.c > +++ b/drivers/gpu/drm/drm_mode_config.c > @@ -533,6 +533,17 @@ void drm_mode_config_cleanup(struct drm_device *dev) > } > EXPORT_SYMBOL(drm_mode_config_cleanup); > > +static u32 full_encoder_mask(struct drm_device *dev) > +{ > + struct drm_encoder *encoder; > + u32 encoder_mask = 0; > + > + drm_for_each_encoder(encoder, dev) > + encoder_mask |= drm_encoder_mask(encoder); > + > + return encoder_mask; > +} > + > /* > * For some reason we want the encoder itself included in > * possible_clones. Make life easy for drivers by allowing them > @@ -544,10 +555,39 @@ static void fixup_encoder_possible_clones(struct > drm_encoder *encoder) > encoder->possible_clones = drm_encoder_mask(encoder); > } > > +static void validate_encoder_possible_clones(struct drm_encoder *encoder) > +{ > + struct drm_device *dev = encoder->dev; > + u32 encoder_mask = full_encoder_mask(dev); > + struct drm_encoder *other; > + > + drm_for_each_encoder(other, dev) { > + WARN(!(encoder->possible_clones & drm_encoder_mask(other)) != > + !(other->possible_clones & drm_encoder_mask(encoder)), Bikeshed: !! as canonical "make this a bool value" might be slightly clearer, but whatever. > + "possible_clones mismatch: " > + "[ENCODER:%d:%s] mask=0x%x possible_clones=0x%x vs. " > + "[ENCODER:%d:%s] mask=0x%x possible_clones=0x%x\n", > + encoder->base.id, encoder->name, > + drm_encoder_mask(encoder), encoder->possible_clones, > + other->base.id, other->name, > + drm_encoder_mask(other), other->possible_clones); > + } > + > + WARN((encoder->possible_clones & drm_encoder_mask(encoder)) == 0 || > + (encoder->possible_clones & ~encoder_mask) != 0, > + "Bogus possible_clones: " > + "[ENCODER:%d:%s] possible_clones=0x%x (full encoder mask=0x%x)\n", > + encoder->base.id, encoder->name, > + encoder->possible_clones, encoder_mask); > +} Since it's next to each another double-checking that the fixup did add the self-clone is probably too much :-) > + > void drm_mode_config_validate(struct drm_device *dev) > { > struct drm_encoder *encoder; > > drm_for_each_encoder(encoder, dev) > fixup_encoder_possible_clones(encoder); > + > + drm_for_each_encoder(encoder, dev) > + validate_encoder_possible_clones(encoder); > } > diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h > index 22d6cdf729f1..3741963b9587 100644 > --- a/include/drm/drm_encoder.h > +++ b/include/drm/drm_encoder.h > @@ -163,6 +163,8 @@ struct drm_encoder { >* any cloning it can leave @possible_clones set to 0. The core will >* automagically fix this up by setting the bit for the encoder itself. >* > + * You will get a WARN if you get this wrong in the driver. Nice. Reviewed-by: Daniel Vetter > + * >* Note that since encoder objects can't be hotplugged the assigned > indices >* are stable and hence known before registering all objects. >*/ > -- > 2.24.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel