From patchwork Tue Oct 26 11:40:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 12584685 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0921C433EF for ; Tue, 26 Oct 2021 11:41:36 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id AC99F60D07 for ; Tue, 26 Oct 2021 11:41:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org AC99F60D07 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 721566E82B; Tue, 26 Oct 2021 11:41:12 +0000 (UTC) Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6B8686E591; Tue, 26 Oct 2021 11:41:07 +0000 (UTC) From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1635248465; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=GlN4Xoy0Y/M8Q0M1CpxcAL0AiL8ioioqGfsGYxp3KAc=; b=atXGj1vAT2SVLpL9o+7T+qCHeniN4MO+Jb8n1niIcFQX0zuyAJriCmlOUGAKQo8NnAVWWH V6T3v30rZGObcV5FSb1/YqivN4AF+MZJAg6LVRyku+iH2hlGOq9rNlLy0XsejZ01tWcxVJ +IqBukAQZ+bwUPdTw/tjbDyF+ObldKIBXGH2fY5MY5K02xYKaesyBbnGH9AanCw3UjmqZK 2cTftsufV3T3DMW5HzYtYnaJ6p3TmaMybPgrrCARwfm5ing9ZoqLRSkQqSY9x9baBGJmQY 20km7Ve34sa5oFtDsGNj8ahggLBIOHffOVghIGR088scgdGVGctCU5bT7hchHw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1635248465; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=GlN4Xoy0Y/M8Q0M1CpxcAL0AiL8ioioqGfsGYxp3KAc=; b=6WqCafDxfmfNMkeDd6oA8r7n4+femnKxhZd4FrZBNXUgphStAYU0Y0hve035wDRPfgMsmS N8XjkXdHYkLVwnAg== To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , David Airlie , Daniel Vetter , Thomas Gleixner , Peter Zijlstra , Sebastian Andrzej Siewior , Clark Williams , Maarten Lankhorst Subject: [PATCH 2/9] drm/i915/gt: Queue and wait for the irq_work item. Date: Tue, 26 Oct 2021 13:40:53 +0200 Message-Id: <20211026114100.2593433-3-bigeasy@linutronix.de> In-Reply-To: <20211026114100.2593433-1-bigeasy@linutronix.de> References: <20211026114100.2593433-1-bigeasy@linutronix.de> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Disabling interrupts and invoking the irq_work function directly breaks on PREEMPT_RT. PREEMPT_RT does not invoke all irq_work from hardirq context because some of the user have spinlock_t locking in the callback function. These locks are then turned into a sleeping locks which can not be acquired with disabled interrupts. Using irq_work_queue() has the benefit that the irqwork will be invoked in the regular context. In general there is "no" delay between enqueuing the callback and its invocation because the interrupt is raised right away on architectures which support it (which includes x86). Use irq_work_queue() + irq_work_sync() instead invoking the callback directly. Reported-by: Clark Williams Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Maarten Lankhorst --- drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c index 209cf265bf746..6e1b9068d944c 100644 --- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c @@ -311,10 +311,9 @@ void __intel_breadcrumbs_park(struct intel_breadcrumbs *b) /* Kick the work once more to drain the signalers, and disarm the irq */ irq_work_sync(&b->irq_work); while (READ_ONCE(b->irq_armed) && !atomic_read(&b->active)) { - local_irq_disable(); - signal_irq_work(&b->irq_work); - local_irq_enable(); + irq_work_queue(&b->irq_work); cond_resched(); + irq_work_sync(&b->irq_work); } }