diff --git a/drivers/gpu/drm/vc4/vc4_txp.c b/drivers/gpu/drm/vc4/vc4_txp.c index ace2d03649ba..82beb8c159f2 100644 --- a/drivers/gpu/drm/vc4/vc4_txp.c +++ b/drivers/gpu/drm/vc4/vc4_txp.c @@ -304,6 +304,12 @@ static void vc4_txp_connector_atomic_commit(struct drm_connector *conn, if (fb->format->has_alpha) ctrl |= TXP_ALPHA_ENABLE; + else + /* + * If TXP_ALPHA_ENABLE isn't set and TXP_ALPHA_INVERT is, the + * hardware will force the output padding to be 0xff. + */ + ctrl |= TXP_ALPHA_INVERT; gem = drm_fb_cma_get_gem_obj(fb, 0); TXP_WRITE(TXP_DST_PTR, gem->paddr + fb->offsets[0]);