From patchwork Fri Sep 2 14:58:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bjorn Helgaas X-Patchwork-Id: 12964326 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1380C54EE9 for ; Fri, 2 Sep 2022 15:26:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236715AbiIBP0S (ORCPT ); Fri, 2 Sep 2022 11:26:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236621AbiIBPZc (ORCPT ); Fri, 2 Sep 2022 11:25:32 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24B9339BAB; Fri, 2 Sep 2022 07:58:44 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 64FEDB82C4E; Fri, 2 Sep 2022 14:58:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E01ABC433D6; Fri, 2 Sep 2022 14:58:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662130721; bh=RT3RQzwcZmsdKMDfRVB08SNXYiMqaAszRBdVwIagBPc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KkAY7R+k7mPZucBQoehE250/BiWxu/qI4+RUJhNkXWiWGuyz+B7yLItRsuAWyfxmh yQVgJxj/yKDqV6d8wzWI4TARqiH+LGj+UK1uQbWeUscrz1JfwPZaORvo+zQ+8SnEi9 ajc6Ctr+6nQ6EZqewpz7OhWFqRC97HnMg5JKVWuTIvCwknz5sMRkyglHwAnF4lV0XP +dgZDLM6NbnmunLb7GMwfhqNZS3IjPZz6vp77CqfrFrBKUFmRyvQ7oiiuXwsZi4tlw PsB8i0eYQgW3f0i8R6No+R62fVV/WYZ5dviR1ovudzcBZUopRiAdpBIA3GsueisYHn B9+GCX3j6mMTQ== From: Bjorn Helgaas To: Kai-Heng Feng , Rajvi Jingar , "Rafael J . Wysocki" Cc: Koba Ko , Mika Westerberg , "David E . Box" , Sathyanarayanan Kuppuswamy , linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Bjorn Helgaas Subject: [PATCH 1/4] PCI/PTM: Preserve PTM Root Select Date: Fri, 2 Sep 2022 09:58:32 -0500 Message-Id: <20220902145835.344302-2-helgaas@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220902145835.344302-1-helgaas@kernel.org> References: <20220902145835.344302-1-helgaas@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Bjorn Helgaas When disabling PTM, there's no need to clear the Root Select bit. We disable PTM during suspend, and we want to re-enable it during resume. Clearing Root Select here makes re-enabling more complicated. Per PCIe r6.0, sec 7.9.15.3, "When set, if the PTM Enable bit is also Set, this Time Source is the PTM Root," so if PTM Enable is cleared, the value of Root Select should be irrelevant. Preserve Root Select to simplify re-enabling PTM. Signed-off-by: Bjorn Helgaas Cc: David E. Box --- drivers/pci/pcie/ptm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c index 368a254e3124..b6a417247ce3 100644 --- a/drivers/pci/pcie/ptm.c +++ b/drivers/pci/pcie/ptm.c @@ -42,7 +42,7 @@ void pci_disable_ptm(struct pci_dev *dev) return; pci_read_config_word(dev, ptm + PCI_PTM_CTRL, &ctrl); - ctrl &= ~(PCI_PTM_CTRL_ENABLE | PCI_PTM_CTRL_ROOT); + ctrl &= ~PCI_PTM_CTRL_ENABLE; pci_write_config_word(dev, ptm + PCI_PTM_CTRL, ctrl); }