From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) (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 BAB0936A364 for ; Tue, 1 Sep 2026 06:50:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788245462; cv=none; b=cw1uMvobi7COpG8rJGRO2gy3T7lUpOhdeH9dcZxDB4KUcliWKBjYLZKSVJ/ObL6o2GD+jVdZWhstGk/hw6ajsPlJ7pQBgPC5ADXKBftLRKmRZK7CQk2WIb/dVF08ya/SwPzl9Q71Ae2Be7fOpiITXEzJXMp6GVvvu06TTn6PuY4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788245462; c=relaxed/simple; bh=c0eFVc6LgKOAuJwHrwZXew5GtKhBEi3uq/gwhAQEPwY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=c4pD6FwIIj8OnS0AP3nBjvzSQ3RjpfVV0wtVuWn1JQb+B9L1xpA/iV76r22oYrnZaD7rlZba3VNHVUjnUJYA+CXxctBrb0+NDTQSM9YK9Nttr/Kbkw1Ql0/6S2n7Z2rkjJZT7j1rKsSDxOKG8BVXlQ1XUirqqmJ4Z8HvvrriJhk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=WFm9I+UT; arc=none smtp.client-ip=115.124.30.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="WFm9I+UT" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1788245449; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=Jb6xdPLG8EuYdMQ/gBekTiRiS+tQQXrON9lxGVmWOmU=; b=WFm9I+UTy2/OhLPGZ3BEjBqDdBjxBTBsgzIgx2/OSygqftWOuO1AmHtnBcEPvlWCXMcgVH8BXMIXX6z0+huwhxV19uNxQffYHwx06iqnu1tW3zRbaawRBZxT42L8V+XC9Vq75TY+wpbeMylliKrSXaz4EcstoM/0xRvJafiviB0= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam011083073210;MF=qinyuntan@linux.alibaba.com;NM=1;PH=DS;RN=17;SR=0;TI=SMTPD_---0XA4XWS6_1788245447; Received: from banye.tbsite.net(mailfrom:qinyuntan@linux.alibaba.com fp:SMTPD_---0XA4XWS6_1788245447 cluster:ay36) by smtp.aliyun-inc.com; Tue, 01 Sep 2026 14:50:49 +0800 From: Qinyun Tan To: dri-devel@lists.freedesktop.org Cc: tzimmermann@suse.de, airlied@redhat.com, jfalempe@redhat.com, kraxel@redhat.com, dmitry.osipenko@collabora.com, hansg@kernel.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, simona@ffwll.ch, leandro.ribeiro@collabora.com, daniels@collabora.com, pekka.paalanen@collabora.com, virtualization@lists.linux.dev, spice-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Qinyun Tan Subject: [PATCH 0/4] drm: create blend mode property on alpha-capable planes of simple drivers Date: Tue, 1 Sep 2026 14:50:41 +0800 Message-ID: <20260901065045.1152136-1-qinyuntan@linux.alibaba.com> X-Mailer: git-send-email 2.43.7 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Since commit 860e748bddcc ("drm: ensure blend mode supported if pixel format with alpha exposed"), drm_mode_config_validate() warns when a plane exposes an alpha pixel format but does not create the "pixel blend mode" property. Several simple/virtual drivers trip this on driver load. I hit the ast one on an ASPEED AST2600 BMC: [PLANE:37:plane-1] pixel format with alpha exposed but blend mode not setup WARNING: drivers/gpu/drm/drm_mode_config.c:872 at drm_mode_config_validate+0x48f/0x510 [drm] ... Call Trace: drm_dev_register+0x1ce/0x290 [drm] ast_pci_probe+0x19d/0x3f0 [ast] local_pci_probe+0x41/0x90 These four drivers share the same gap; this series covers ast, qxl, virtio-gpu and vboxvideo. These planes have always blended with pre-multiplied alpha: the hardware (or host-side compositor for the virtual drivers) is fixed function with no configurable blend mode, and userspace has historically assumed pre-multiplied blending when the property is not attached, which is also the documented default of the property. So each patch simply exposes the "pixel blend mode" property advertising only DRM_MODE_BLEND_PREMULTI, making the existing semantics explicit and silencing the warning. No functional change. This follows the same approach as the already-merged i915 and nouveau fixes: 67e955e073c6 ("drm/i915/display: expose blend mode on alpha-capable planes") df0311845915 ("drm/nouveau/kms/nv50-: Unconditionally create blend_mode prop for wndws") The ast patch is verified on AST2600 hardware: the warning is gone and the cursor plane now exposes the "pixel blend mode" property with Pre-multiplied as the only and current value. The qxl, virtio and vboxvideo patches follow the identical pattern and are compile-tested. Qinyun Tan (4): drm/ast: create blend mode property on cursor plane drm/qxl: create blend mode property on primary and cursor planes drm/virtio: create blend mode property on cursor plane drm/vboxvideo: create blend mode property on planes drivers/gpu/drm/ast/ast_cursor.c | 3 +++ drivers/gpu/drm/qxl/qxl_display.c | 4 ++++ drivers/gpu/drm/vboxvideo/vbox_mode.c | 4 ++++ drivers/gpu/drm/virtio/virtgpu_plane.c | 4 ++++ 4 files changed, 15 insertions(+) -- 2.43.7