From patchwork Tue Dec 14 14:02:55 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: 12676095 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 28051C433F5 for ; Tue, 14 Dec 2021 14:03:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AEFFC10E52D; Tue, 14 Dec 2021 14:03:13 +0000 (UTC) Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id A56FC10E119; Tue, 14 Dec 2021 14:03:11 +0000 (UTC) From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1639490589; 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=GjnG6XrKnKaWG2pzVaB+YFqwmh6fKpdCuYM0Qwmv/68=; b=mzPZaSVYRuE21yevyqU3TVGt4WSGm3Msvl+NwWEWepwnzq62g3hOD7VC6CAsNsn+ee4XK9 WAyJLokUsLzhjfEp3kd35mxknERuPF2QQQYMffnAI8dbgNIRwULkkyudXSbMVrKiQT1IHk Sp2EqCLidO0+2gC95cncg94rYP3JUFsznlQiCiJ/En81DRIeXYvaaAu7fS5eVeTS6v2zX/ oYSNTiUCAdSsWFzLiXF1BF4AWINdt+BoWqqeId8IZNyIewdlnIgkeS8RFicgpPxszfAucl +yBp7fB1DGlgfaT05Fnv+G0JeBrc4WeGmBdOEQr9GzgCyt+i3ygZD4m9l/+GdQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1639490589; 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=GjnG6XrKnKaWG2pzVaB+YFqwmh6fKpdCuYM0Qwmv/68=; b=zrytUs9VjyWQ2kqRZ30q8cW6rCHEOZpj1AEoDR8O1xObd/eqoqEjLPlJMPA88MBlseAmzk hGjQrMQDzlucxEAQ== To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Date: Tue, 14 Dec 2021 15:02:55 +0100 Message-Id: <20211214140301.520464-3-bigeasy@linutronix.de> In-Reply-To: <20211214140301.520464-1-bigeasy@linutronix.de> References: <20211214140301.520464-1-bigeasy@linutronix.de> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 2/8] 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 , 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..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); } }