From patchwork Wed Sep 8 18:57:02 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: 12481733 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD6DAC433EF for ; Wed, 8 Sep 2021 19:05:00 +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 9DD1C61074 for ; Wed, 8 Sep 2021 19:05:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 9DD1C61074 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 870136E2B8; Wed, 8 Sep 2021 19:04:55 +0000 (UTC) X-Greylist: delayed 461 seconds by postgrey-1.36 at gabe; Wed, 08 Sep 2021 19:04:51 UTC Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9AD0C6E296; Wed, 8 Sep 2021 19:04:51 +0000 (UTC) From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1631127427; 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=uojuMhK8EFqg62qCIyHIniDCbF3TH69reqpSG63YWT0=; b=F1L/ndDQDV6uDNe9gJlyb5O9Ww3altx4PMFmNewqMQrxFjRyzKpJo4FReeBdwjyZtZuzpt 5NG5NAoJbJ8K89xHjE1ka+0HUHWplx+xaSu88aAgBoK4bwHzQYfR9mXN7pFoZZvQLBlLzc i0U8JGuEf4Vq+aqOzIQvK3O2ogNUhSDyQTv7F88Z6fcy+WhQjcKylHV0lADAVGdAsWy6qo +DvG1yu5Wr2LLvqf+Lg1tStvfaLxz+Gd8hOeeuPaMS7DpEW3jBHVUfjITJQU6hcOiB7uWF rhRIQpC4W4xQAkQjah3obbkx41wdTtB6QxzrRQuNJlzkELHVtQMxsA8k0haf6g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1631127427; 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=uojuMhK8EFqg62qCIyHIniDCbF3TH69reqpSG63YWT0=; b=lxdFr/YJDauQKuNKOf4Ph1bxaENUVYRVp/729ws38DPEqjzPRzDnWvEKTwjd805AYCcopS t7TDe2ogcO+H2jDg== To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: David Airlie , Daniel Vetter , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Chris Wilson , Peter Zijlstra , Thomas Gleixner , Clark Williams , Sebastian Andrzej Siewior Subject: [PATCH 1/2] drm/i915/gt: Queue and wait for the irq_work item. Date: Wed, 8 Sep 2021 20:57:02 +0200 Message-Id: <20210908185703.2989414-2-bigeasy@linutronix.de> In-Reply-To: <20210908185703.2989414-1-bigeasy@linutronix.de> References: <20210908185703.2989414-1-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 --- 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 38cc42783dfb2..594dec2f76954 100644 --- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c @@ -318,10 +318,9 @@ 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); } }