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: shmobile: Fix white screen after resume when LCDC is stopped Date: Sun, 22 Mar 2026 04:28:52 +1000 Message-ID: In-Reply-To: <20260319083207.17195-1-phucduc.bui@gmail.com> References: <20260319083207.17195-1-phucduc.bui@gmail.com> X-Mailer: Claude Code Patch Reviewer Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit MIME-Version: 1.0 Overall Series Review Subject: drm: shmobile: Fix white screen after resume when LCDC is stopped Author: phucduc.bui@gmail.com Patches: 1 Reviewed: 2026-03-22T04:28:52.005399 --- This is a single, well-motivated bugfix patch for the shmobile LCDC driver. The problem is clearly described: after suspend/resume, both register sets (A and B) are reset to 0, but the original code only wrote to the mirror (Set B) and relied on a Frame End interrupt to trigger the hardware register switching. When the controller is stopped (DO=0), no Frame End interrupt occurs, so Set A stays at 0 and the display shows white. The fix is correct and minimal. It checks whether the display output is active (LDCNT2R_DO) and uses the appropriate write path: - **DO=1 (running):** Use `lcdc_write_mirror()` + toggle `LDRCNTR_MRS` as before (the normal double-buffered update path). - **DO=0 (stopped):** Use `lcdc_write()` which writes to both Set A and Set B directly, ensuring valid addresses are present when output is re-enabled. The patch has Tested-by and Reviewed-by from the subsystem maintainer (Geert Uytterhoeven). It looks ready to merge. --- Generated by Claude Code Patch Reviewer