From patchwork Fri Mar 11 12:30:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 12777931 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 01672C433F5 for ; Fri, 11 Mar 2022 12:30:54 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 12CEC10E964; Fri, 11 Mar 2022 12:30:48 +0000 (UTC) Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5AA6210E960; Fri, 11 Mar 2022 12:30:46 +0000 (UTC) From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1647001844; 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=t4G8akgUa9jCEUhZnTTe8VSqD7DwM4uu9SxRJBZp1fY=; b=OVtRWUOPbcaae1PnsieQuLEoPeD2d024oeAZgW/NAR6wi+7N6tPGVYbOocS0BOQtchaC5W 8LzLgRInDb9wC3Kutv1/2kSPcqvI4Szwz1+G+wuVmroK2wlqDOKEn9M4rvixJoqTvDpD1k 47CVXAZK7f+rq8EE4hpYZnijZkN9U/JFEpuaoItTgqTC4aJXlEZ3imZe+KrhL1nDcokkhh f6glSXRltm45XMNyFm5i4dxZemGtkFzujvm3zptjmXxY6fSUTSsyMeKX1A+24pOGAsIbAV pVb/L2VEOzsbOpoPK5zlWSIXcp3YAX/nWPZJiRzv6nfBZsV2uaPzod+PgowEFQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1647001844; 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=t4G8akgUa9jCEUhZnTTe8VSqD7DwM4uu9SxRJBZp1fY=; b=c9THJTz3V5JvEJzQ8qGudsCTludNxLtOlY65VJY2+HBhmEcfFCEKCByPHvwAyVc44lP16B L2SyWA7uZW2ScGAA== To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Date: Fri, 11 Mar 2022 13:30:31 +0100 Message-Id: <20220311123032.4078431-2-bigeasy@linutronix.de> In-Reply-To: <20220311123032.4078431-1-bigeasy@linutronix.de> References: <20220311123032.4078431-1-bigeasy@linutronix.de> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 1/2] drm/i915/gt: Queue and wait for the irq_work item. X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Airlie , Sebastian Andrzej Siewior , Clark Williams , Rodrigo Vivi , Thomas Gleixner Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" 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..98efeb97a6ba6 100644 --- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c @@ -311,9 +311,8 @@ 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); + irq_work_sync(&b->irq_work); cond_resched(); } }