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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 38C41C282EC for ; Mon, 10 Mar 2025 15:38:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=iP5ye8zT3XIsvH+PNGvaZLaxESkuwYpIjYNZsfXOW/Q=; b=OKM4DzVsO71iEJ2bEF3UBtRv50 /2d3xXuesHuJ/UrLqnKN4hra4jCfFOQzcOJZ+gTd/NWVjT4TuakbNPneMpScOvCqXe2JU3ax6RFrz 1P4XLG5niYyVEmvSiCq4KH8UO/9qh5gSrrP6P/p3IYpguuDPymRiA6fusdMMMFo+k3w4/8pG/0v9G 4cUHWiPyrSUvq/v+RXBGnMs1HwhgG3RXqFE6MNuIAbgRVThXuylLHQi0nqq36ZcPwAtsiuMcJeJaX +4dmKK43PGExMSc0OA2RuqGKXu6see9LsXO7W2K29lUYPeOOd2kwwr37us8P97UhzMLrKYJxip+Vs Yg17QBuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1trfD7-00000003CZ9-0LD4; Mon, 10 Mar 2025 15:38:33 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1treHG-00000002xEJ-2y64 for linux-nvme@lists.infradead.org; Mon, 10 Mar 2025 14:38:47 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id E005B5C667A; Mon, 10 Mar 2025 14:36:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 035C7C4CEE5; Mon, 10 Mar 2025 14:38:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741617525; bh=qPjt2HNHOrU8xnC8hYF6piHqZ8fvgELpU+TTqGWaDSc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZoZLQtB2CfOzsZYWHAHNJ5ZdOVspZBxyum3Fuhr4XeNvl4E2Y9m2InKFy9gd1BFOE 7QXxilfsOydkfSR3Xy3pRwfgO8MhwgCyp+uCMtuytrB3sNNFUxc7mt1mU2JTsaubtJ IlTL/40HvUMpA1tTeK+u9BppgC54ZH9kZO4GuoOpYz++nGf+Nir/nMbVDd/8LGPukI AzobZyZA9N2HVitqjZMN4v0Y9q0QWRCFByS+CsvQgF4c/k8aBQhW/YnxyZRdYo3ItX L5hruk4XaGQLt8EUWA4E7Fvkq31U+BPl5ZEXDWXXghKOt+7BVDc7w7yZ3bcelz3VY9 gOA72rRSFE4VA== Date: Mon, 10 Mar 2025 08:38:42 -0600 From: Keith Busch To: Nilay Shroff Cc: Keith Busch , linux-nvme@lists.infradead.org, hch@lst.de, sagi@grimberg.me Subject: Re: [PATCH] nvme-pci: fix stuck reset on concurrent DPC and HP Message-ID: References: <20250307002424.3655342-1-kbusch@meta.com> <46617499-17ea-44b9-9ed0-1fb5d238f54f@linux.ibm.com> <3dcf210e-a714-4572-bd5b-01c66c594fd9@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3dcf210e-a714-4572-bd5b-01c66c594fd9@linux.ibm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250310_073846_790975_FFB6B69A X-CRM114-Status: GOOD ( 10.69 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Sat, Mar 08, 2025 at 12:57:50PM +0530, Nilay Shroff wrote: > On 3/7/25 8:54 PM, Keith Busch wrote: > > If the pciehp removal starts after reset work's controller > > initialization, then nothing stops the work from sending new admin > > commands, and nothing will complete them. This causes the error_resume > > to wait for something that will never happen. > > Ok makes sense, this appears to be a tight race condition and may not be > limited to one platform. This should be possible even on PPC. Yeah, I also thought it was a very unlikely condition to hit, but I have a platform that deadlocks here almost every time a DPC event occurs.