From owner-dev-commits-src-all@freebsd.org Fri Oct 1 16:56:25 2021 Return-Path: Delivered-To: dev-commits-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id DABB36B298D; Fri, 1 Oct 2021 16:56:25 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4HLbqF5W69z4k2k; Fri, 1 Oct 2021 16:56:25 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 9E92122ECA; Fri, 1 Oct 2021 16:56:25 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 191GuPKE004106; Fri, 1 Oct 2021 16:56:25 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 191GuPrA004105; Fri, 1 Oct 2021 16:56:25 GMT (envelope-from git) Date: Fri, 1 Oct 2021 16:56:25 GMT Message-Id: <202110011656.191GuPrA004105@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Warner Losh Subject: git: 77054a897f64 - main - nvme: Explain a workaround a little better MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: imp X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 77054a897f6440632267e75ebe31793c7555b79e Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 01 Oct 2021 16:56:26 -0000 The branch main has been updated by imp: URL: https://cgit.FreeBSD.org/src/commit/?id=77054a897f6440632267e75ebe31793c7555b79e commit 77054a897f6440632267e75ebe31793c7555b79e Author: Warner Losh AuthorDate: 2021-10-01 15:53:10 +0000 Commit: Warner Losh CommitDate: 2021-10-01 16:56:10 +0000 nvme: Explain a workaround a little better The don't touch the mmio of the drive after we do a EN 1->0 transition is only for a tiny number of dirves that have this unforunate issue. Sponsored by: Netflix --- sys/dev/nvme/nvme_ctrlr.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/sys/dev/nvme/nvme_ctrlr.c b/sys/dev/nvme/nvme_ctrlr.c index 10b30c584f71..eb95fa33b90b 100644 --- a/sys/dev/nvme/nvme_ctrlr.c +++ b/sys/dev/nvme/nvme_ctrlr.c @@ -318,10 +318,10 @@ nvme_ctrlr_disable(struct nvme_controller *ctrlr) cc &= ~NVME_CC_REG_EN_MASK; nvme_mmio_write_4(ctrlr, cc, cc); + /* - * Some drives have issues with accessing the mmio after we - * disable, so delay for a bit after we write the bit to - * cope with these issues. + * A few drives have firmware bugs that freeze the drive if we access + * the mmio too soon after we disable. */ if (ctrlr->quirks & QUIRK_DELAY_B4_CHK_RDY) pause("nvmeR", MSEC_2_TICKS(B4_CHK_RDY_DELAY_MS));