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/i915/display: All patches to make PREEMPT_RT work on i915 + xe. Date: Wed, 11 Mar 2026 13:21:17 +1000 Message-ID: In-Reply-To: <20260310115709.2276203-1-dev@lankhorst.se> References: <20260310115709.2276203-1-dev@lankhorst.se> 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/i915/display: All patches to make PREEMPT_RT work on i915 + xe. Author: Maarten Lankhorst Patches: 31 Reviewed: 2026-03-11T13:21:17.008561 --- This is v7 of a 26-patch series to make the i915 (and xe) display driver work with PREEMPT_RT kernels. The core strategy is sound: instead of converting all vblank-related spinlocks to raw spinlocks, the series introduces a 2-stage arming mechanism for vblank events and vblank work, so that the critical section with interrupts disabled only needs to perform a simple `WRITE_ONCE()` rather than acquire sleeping locks. The series covers: 1. **DRM core changes** (patches 1-2): 2-stage vblank work/event arming 2. **Display critical section rework** (patches 3-7): Converting i915 display to use the new 2-stage mechanism, removing locks from the vblank evade critical section 3. **RT-specific fixes** (patches 8-18): `_fw` register access variants, lock conversions, RT-aware busy loops 4. **Selftests/config** (patches 19-26): Selftest fixes, removing `!PREEMPT_RT` dependency, CI hacks **Strengths:** The overall approach of 2-stage arming is elegant and avoids a massive raw spinlock conversion. Many individual fixes (LPE audio, execlists locking, GUC busy loop) are well-motivated with lockdep splats. **Concerns:** - Patches 24-25 are clearly FOR-CI/debug patches that should not be merged. Patch 24 force-enables PREEMPT_RT and removes the vblank evade debug config. Patch 25 bumps lockdep stack trace limits as a CI workaround. - Patch 21 has a TODO in its commit message, suggesting unfinished work. - Several patches lack Signed-off-by chains or commit message body (patch 19). - The mbox ordering doesn't match the patch numbering, which may cause confusion. --- Generated by Claude Code Patch Reviewer