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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 6F81CC432C0 for ; Tue, 3 Dec 2019 07:48:37 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 43AD52053B for ; Tue, 3 Dec 2019 07:48:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="VNGnpdFv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 43AD52053B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0P05TN1lqRMjF5r7e8hbTREO6sBTGVnmNXAL0l8m9Fk=; b=VNGnpdFvfy2HJd cJbcKwcZjOVnELREH5KIrpZyJrRgAKmJJVTefzDQ3t6rNhTpwT7b7TU1l+/3Zemr9qxLe8vjfc8dv LJmW5QwAx1xpnvdYf/HgzN2XPXlxuFLUkK7Jzi4/leA2iByoqcqcjWzbTJaEkCuVsKbxXil+oeDuP V9+QiDHlSGaCDkGqypp1d8PVgJgi28ylG+DQ5PJeEXg/8LL1TMuBc1SFOcJd1fGfnRmA5BCh8ltpe KSj/XQnBN5Bc+njyyONl/Q8OY7VdnjcOpTcfqysTMJXZUV2qxsCrKY6YKg59Bvzw9JewGSmBYaHcY knYfG1DA9KhNKNNHVGFQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ic2vC-0001sN-5m; Tue, 03 Dec 2019 07:48:34 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1ic2u6-0000uL-BC for linux-nvme@lists.infradead.org; Tue, 03 Dec 2019 07:47:27 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 764C968BFE; Tue, 3 Dec 2019 08:47:23 +0100 (CET) Date: Tue, 3 Dec 2019 08:47:23 +0100 From: Christoph Hellwig To: Keith Busch Subject: Re: [PATCHv2 2/2] nvme/pci: Mask device interrupts for threaded handlers Message-ID: <20191203074723.GE23881@lst.de> References: <20191202222058.2096-1-kbusch@kernel.org> <20191202222058.2096-3-kbusch@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191202222058.2096-3-kbusch@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191202_234726_545115_1D54517C X-CRM114-Status: UNSURE ( 8.02 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: sagi@grimberg.me, bigeasy@linutronix.de, linux-nvme@lists.infradead.org, ming.lei@redhat.com, helgaas@kernel.org, tglx@linutronix.de, hch@lst.de Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Dec 03, 2019 at 07:20:58AM +0900, Keith Busch wrote: > +static irqreturn_t nvme_irq_thread(int irq, void *data) > +{ > + struct nvme_queue *nvmeq = data; > + > + nvme_irq(irq, data); > + if (to_pci_dev(nvmeq->dev->dev)->msix_enabled) > + __pci_msix_desc_mask_irq(irq_get_msi_desc(irq), 0); > + else > + writel(1 << nvmeq->cq_vector, nvmeq->dev->bar + NVME_REG_INTMC); So independent of the indirection issue can we have a theory of operation on why not using a read to flush the posted writes to disable/enable the interrupt (either variant) here is fine? Let's assume we have a worse case implementation where no write ever gets delivered to the device until we do a read neither of them will ever hit the device as we don't really do MMIO reads in nvme during normal operation. _______________________________________________ linux-nvme mailing list linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme