From mboxrd@z Thu Jan 1 00:00:00 1970 From: Claude Code Review Bot To: dri-devel-reviews@example.com Subject: Claude review: drm/drm_blend: allow blend mode property without PREMULTI Date: Tue, 05 May 2026 08:17:26 +1000 Message-ID: In-Reply-To: <20260504140630.68707-1-leandro.ribeiro@collabora.com> References: <20260504140630.68707-1-leandro.ribeiro@collabora.com> X-Mailer: Claude Code Patch Reviewer Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Overall Series Review Subject: drm/drm_blend: allow blend mode property without PREMULTI Author: Leandro Ribeiro Patches: 3 Reviewed: 2026-05-05T08:17:26.131070 --- This is a 2-patch series to relax the DRM blend mode property creation API = so that drivers whose hardware only supports COVERAGE (no PREMULTI) can exp= ose blend mode. Patch 1 removes the PREMULTI requirement; patch 2 adds a ha= rd enforcement that any driver exposing alpha (via alpha property or pixel = formats with alpha channel) **must** also expose the blend mode property, o= r `drm_dev_register()` will fail. The motivation is sound =E2=80=94 hardware exists that only does COVERAGE b= lending, and the current API artificially prevents those drivers from being= upstreamed. However, **patch 2 has a serious problem**: the enforcement wi= ll break multiple existing in-tree drivers that are currently working and d= o not call `drm_plane_create_blend_mode_property()`. **Affected drivers found** (alpha_property set but no blend_mode_property): - `sun4i/sun8i_ui_layer.c` - `sun4i/sun8i_vi_layer.c` - `atmel-hlcdc/atmel_hlcdc_plane.c` - `stm/ltdc.c` - `xlnx/zynqmp_kms.c` - `logicvc/logicvc_layer.c` None of these use the deprecated `.load` callback, so the enforcement is no= t bypassed. Additionally, the pixel-format alpha check (`fmt->has_alpha`) w= ill catch even more drivers =E2=80=94 virtually any driver that lists ARGB8= 888 among its supported formats but doesn't set up blend mode. This is an e= xtremely broad net that could break many more drivers beyond the alpha_prop= erty ones listed above. The series needs either: (a) companion patches to fix all affected in-tree = drivers before the enforcement is turned on, or (b) a softer enforcement (W= ARN instead of error-return) with a plan to harden it later. --- --- Generated by Claude Code Patch Reviewer