From nobody Thu Dec 18 08:10:27 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4DB92381B1 for ; Fri, 27 Sep 2024 20:40:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727469616; cv=none; b=CAn6rbLNqvaFbRjtl68i3FerzIddgGqDqzJbQcwQ3WfsoZZPuieLaxg0fMKJUGZBbx+1pdNR7uorquPkZPUxcG+/sk0qKgw9Zx03NtXv2mdYEItAYuxX7wNLvYe6a25g2skcWqvAbWrBIDxRl78IcqEuq51QMsD8LjeD0zL/uPg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727469616; c=relaxed/simple; bh=sqgzfonPHEkQo5wKiEeEuNAU2dhBeoHHLU5S4ow0UWg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=iddCAnd29ddrhISskHB/9N2JGJ8vWDxyOwBC8X8nbed6btd5Y+A5KlaLUmP/BT/HnbF7bsSR38yGvmFALXSd1u13PlDmEgTxJ4OYUh/rFTaow2GEwvYrhK1htm/NFDqPDdzixwSBDfHewHFCrCT60Jgl0VOf0/wKL8RZDLFbsRA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=T4/PpyEy; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="T4/PpyEy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1727469613; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=yRSI0RXAYJUqZWDNqYmjtNLAHKeav7N5jvF/NFDhhMM=; b=T4/PpyEyVLwm8uHmz1az/pMX4q2fEweBMrsG9t6P/5wGXxec5xm656oucPorwKQ+oITEyF T2ZehdYFqbzjSqptFqei8Tygr1kds1a4mDM3hKl5rUjqCrmQ2KB+vKyiHMRkSBy0Kw/A8i lpXedI3kDD2rIdo6pxolU4Cz5aZRcOw= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-265-IDD_XYF6N_OKUqGWhIqPIw-1; Fri, 27 Sep 2024 16:40:10 -0400 X-MC-Unique: IDD_XYF6N_OKUqGWhIqPIw-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (unknown [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9D83C1934C81; Fri, 27 Sep 2024 20:40:08 +0000 (UTC) Received: from chopper.redhat.com (unknown [10.22.32.36]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 6C21219560A3; Fri, 27 Sep 2024 20:40:05 +0000 (UTC) From: Lyude Paul To: dri-devel@lists.freedesktop.org Cc: Stefan Agner , Daniel Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , stable@vger.kernel.org, linux-kernel@vger.kernel.org (open list) Subject: [PATCH] drm/vblank: Require a driver register vblank support for 0 or all CRTCs Date: Fri, 27 Sep 2024 16:39:47 -0400 Message-ID: <20240927203946.695934-2-lyude@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Content-Type: text/plain; charset="utf-8" Currently, there's nothing actually stopping a driver from only registering vblank support for some of it's CRTCs and not for others. As far as I can tell, this isn't really defined behavior on the C side of things - as the documentation explicitly mentions to not use drm_vblank_init() if you don't have vblank support - since DRM then steps in and adds its own vblank emulation implementation. So, let's fix this edge case and check to make sure it's all or none. Signed-off-by: Lyude Paul Fixes: 3ed4351a83ca ("drm: Extract drm_vblank.[hc]") Cc: Stefan Agner Cc: Daniel Vetter Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Simona Vetter Cc: dri-devel@lists.freedesktop.org Cc: # v4.13+ --- drivers/gpu/drm/drm_vblank.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index 94e45ed6869d0..4d00937e8ca2e 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -525,9 +525,19 @@ static void drm_vblank_init_release(struct drm_device = *dev, void *ptr) */ int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs) { + struct drm_crtc *crtc; int ret; unsigned int i; =20 + // Confirm that the required vblank functions have been filled out for al= l CRTCS + drm_for_each_crtc(crtc, dev) { + if (!crtc->funcs->enable_vblank || !crtc->funcs->disable_vblank) { + drm_err(dev, "CRTC vblank functions not initialized for %s, abort\n", + crtc->name); + return -EINVAL; + } + } + spin_lock_init(&dev->vbl_lock); spin_lock_init(&dev->vblank_time_lock); =20 base-commit: 22512c3ee0f47faab5def71c4453638923c62522 --=20 2.46.1