From: Maxime Ripard <maxime@xxxxxxxxxx> commit 47a50743031ad4138050ae6d266ddd3dfe845ead upstream. The vc4_set_crtc_possible_masks is meant to run over all the encoders and then set their possible_crtcs mask to their associated pixelvalve. However, since the commit 39fcb2808376 ("drm/vc4: txp: Turn the TXP into a CRTC of its own"), the TXP has been turned to a CRTC and encoder of its own, and while it does indeed register an encoder, it no longer has an associated pixelvalve. The code will thus run over the TXP encoder and set a bogus possible_crtcs mask, overriding the one set in the TXP bind function. In order to fix this, let's skip any virtual encoder. Cc: <stable@xxxxxxxxxxxxxxx> # v5.9+ Fixes: 39fcb2808376 ("drm/vc4: txp: Turn the TXP into a CRTC of its own") Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20210507150515.257424-3-maxime@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/vc4/vc4_crtc.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -1042,6 +1042,9 @@ static void vc4_set_crtc_possible_masks( struct vc4_encoder *vc4_encoder; int i; + if (encoder->encoder_type == DRM_MODE_ENCODER_VIRTUAL) + continue; + vc4_encoder = to_vc4_encoder(encoder); for (i = 0; i < ARRAY_SIZE(pv_data->encoder_types); i++) { if (vc4_encoder->type == encoder_types[i]) {