From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F1328C4453A for ; Wed, 21 Jan 2026 13:53:45 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B7D6F10E791; Wed, 21 Jan 2026 13:53:45 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=lankhorst.se header.i=@lankhorst.se header.b="jjNA505D"; dkim-atps=neutral Received: from lankhorst.se (lankhorst.se [141.105.120.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id F205010E7DB; Wed, 21 Jan 2026 13:53:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=lankhorst.se; s=default; t=1769003620; bh=ohJAyXokG1DXJlCLrQJRh/QxThVSMLY/wxocRwSmqYU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jjNA505DhVbaZDm7vA4qGjQh8tJMemLJ8mw+Q7BtRI9398yVoZdaR7RO4+tFYxRFw 4/2s+MGpxtS5WubxENsafVSVj1sHUcT3it7yax74dj6o8JGnj1bsbthMS/3CXfeODz aDwQ5gr+wtZ11nmrMEFQhgbibYu7IOS5Zec1qGZhrzIJimbJpQd9NTPkG94vMiRwj/ M+QKTKMi+2NED21hT0VC5ELZjD0SGC7ZnoFb+eSu9RCBqvRnLDGkhOTnsHrMuQ2NW+ 0DDGM+h50/jo3wBp+AAAq1S7EaczOFjZeSkiWHpv06X57xThyPHUFddisY+AA7m/2X uc1g7I9f6bT4A== From: Maarten Lankhorst To: intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org Cc: Maarten Lankhorst Subject: [i915-rt v5 09/21] drm/i915/display: Enable interrupts earlier on PREEMPT_RT Date: Wed, 21 Jan 2026 14:53:05 +0100 Message-ID: <20260121135318.651622-10-dev@lankhorst.se> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260121135318.651622-1-dev@lankhorst.se> References: <20260121135318.651622-1-dev@lankhorst.se> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" The last part of the vblank evasion is about updating bookkeeping, not programming hardware registers. The interrupts cannot stay disabled here on PREEMPT_RT since the spinlocks get converted to mutexes. There's still a small race in VRR that needs to be addressed, and in the other worst case there is a delay of a vblank completion if the vblank is fired and we schedule on the next vblank, this needs to be addressed separately. Signed-off-by: Maarten Lankhorst --- drivers/gpu/drm/i915/display/intel_crtc.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c index cb31c9c1c2525..84ab737c50918 100644 --- a/drivers/gpu/drm/i915/display/intel_crtc.c +++ b/drivers/gpu/drm/i915/display/intel_crtc.c @@ -703,6 +703,14 @@ void intel_pipe_update_end(struct intel_atomic_state *state, intel_crtc_has_type(new_crtc_state, INTEL_OUTPUT_DSI)) icl_dsi_frame_update(new_crtc_state); +#if IS_ENABLED(CONFIG_PREEMPT_RT) + /* + * Timing sensitive register writing completed, non-deterministic + * locking from here on out. + */ + local_irq_enable(); +#endif + /* We're still in the vblank-evade critical section, this can't race. * Would be slightly nice to just grab the vblank count and arm the * event outside of the critical section - the spinlock might spin for a @@ -750,7 +758,9 @@ void intel_pipe_update_end(struct intel_atomic_state *state, if (!state->base.legacy_cursor_update) intel_vrr_send_push(NULL, new_crtc_state); +#if !IS_ENABLED(CONFIG_PREEMPT_RT) local_irq_enable(); +#endif if (intel_parent_vgpu_active(display)) goto out; -- 2.51.0