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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C09BFC433EF for ; Wed, 25 May 2022 09:08:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240921AbiEYJIO (ORCPT ); Wed, 25 May 2022 05:08:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237139AbiEYJGF (ORCPT ); Wed, 25 May 2022 05:06:05 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A300986EA; Wed, 25 May 2022 02:04:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=aytZGHL355zCILKlDlAi55WV8/cPE4V7Zd3KNNFli8M=; b=NOIgdNzY8ZBAFLYH297kCYDypt AdYAJrJVvAu83LlqfVnmjxPiEWYzD/GoJJmuYRk/q4wPFwGvk0hjwXzrkcJ//+k5n/Zo9MnzVPe6h PECJBVytALrBXZSdl7JB0cTlggz9HnLa35J7WFNme1ZFdtZkJsJ563uKsa84yPQkNsXcbIoHNbXGw 4h/uhpXRPKn46LWy2YhuPaJ9V/kDpI6axmKLQgB5mbrPEkavlJigcbL72L/W70fLwjmlXUCwReAwB Ts3sjYcwk7Bhzckvbge09C7h8/jUlc+OaGTgf3rkPUIIDWTKIk13Gdc3VaKgvu94tfPnoc5rMVekv iatzWMqA==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1ntmwL-00AWIV-7j; Wed, 25 May 2022 09:04:25 +0000 Date: Wed, 25 May 2022 02:04:25 -0700 From: Christoph Hellwig To: Mario Limonciello Cc: Damien Le Moal , "open list:LIBATA SUBSYSTEM (Serial and Parallel ATA drivers)" , open list , hdegoede@redhat.com Subject: Re: [PATCH 3/3] ahci: Document the loss of hotplug by new LPM policy Message-ID: References: <20220524170508.563-1-mario.limonciello@amd.com> <20220524170508.563-4-mario.limonciello@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220524170508.563-4-mario.limonciello@amd.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 24, 2022 at 12:05:08PM -0500, Mario Limonciello wrote: > Per AHCI spec v1.3.1, "7.3 Native Hot Plug Support", once LPM is > enabled hotplug support needs to be disabled. > > The LPM code always followed this and disabled the port when no > drives were connected, but as more machines will be exposed to > this code it might be an unexpected behavior to some users. > > Add a note to parameter documentation to explain the new behavior. > > Link: https://bugs.launchpad.net/bugs/1971576 > Signed-off-by: Mario Limonciello > --- > Documentation/admin-guide/kernel-parameters.txt | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 9e6bd212004d..4dcd9a3ba4a5 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -279,6 +279,13 @@ > 3 => Medium power with Device Initiated PM enabled > 4 => Minimum power > > + NOTE: Enabling LPM when no drive is connected will disable > + the port which means hotplug will not work. > + > + If hotplug is an important use case, this can be modified This has two overly long lines.