Commit 0df10823 authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm: Validate encoder->possible_crtcs 



WARN if the encoder possible_crtcs is effectively empty or contains
bits for non-existing crtcs.

v2: Move to drm_mode_config_validate() (Daniel)
    Make the docs say we WARN when this is wrong (Daniel)
    Extract full_crtc_mask()

Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200211162208.16224-7-ville.syrjala@linux.intel.com


Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 74d2aacb

drivers/gpu/drm/drm_mode_config.c

+26 −1
Original line number Diff line number Diff line
@@ -581,6 +581,29 @@ static void validate_encoder_possible_clones(struct drm_encoder *encoder) 
	     encoder->possible_clones, encoder_mask);

}



static u32 full_crtc_mask(struct drm_device *dev)

{

	struct drm_crtc *crtc;

	u32 crtc_mask = 0;



	drm_for_each_crtc(crtc, dev)

		crtc_mask |= drm_crtc_mask(crtc);



	return crtc_mask;

}



static void validate_encoder_possible_crtcs(struct drm_encoder *encoder)

{

	u32 crtc_mask = full_crtc_mask(encoder->dev);



	WARN((encoder->possible_crtcs & crtc_mask) == 0 ||

	     (encoder->possible_crtcs & ~crtc_mask) != 0,

	     "Bogus possible_crtcs: "

	     "[ENCODER:%d:%s] possible_crtcs=0x%x (full crtc mask=0x%x)\n",

	     encoder->base.id, encoder->name,

	     encoder->possible_crtcs, crtc_mask);

}



void drm_mode_config_validate(struct drm_device *dev)

{

	struct drm_encoder *encoder;
@@ -588,6 +611,8 @@ void drm_mode_config_validate(struct drm_device *dev) 
	drm_for_each_encoder(encoder, dev)

		fixup_encoder_possible_clones(encoder);



	drm_for_each_encoder(encoder, dev)

	drm_for_each_encoder(encoder, dev) {

		validate_encoder_possible_clones(encoder);

		validate_encoder_possible_crtcs(encoder);

	}

}

include/drm/drm_encoder.h

+1 −1
Original line number Diff line number Diff line
@@ -142,7 +142,7 @@ struct drm_encoder { 
	 * the bits for all &drm_crtc objects this encoder can be connected to

	 * before calling drm_dev_register().

	 *

	 * In reality almost every driver gets this wrong.

	 * You will get a WARN if you get this wrong in the driver.

	 *

	 * Note that since CRTC objects can't be hotplugged the assigned indices

	 * are stable and hence known before registering all objects.

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