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 F2CAAEB8FA5 for ; Wed, 6 Sep 2023 07:59:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232434AbjIFH7m (ORCPT ); Wed, 6 Sep 2023 03:59:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230070AbjIFH7l (ORCPT ); Wed, 6 Sep 2023 03:59:41 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95DFBCF for ; Wed, 6 Sep 2023 00:59:37 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C370C433C7; Wed, 6 Sep 2023 07:59:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1693987177; bh=eApZ/gxYAVJvYlh0rCNB6vlYoBqPdp8tWa9s/pXwUas=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=P88KiSm4bFRtpenUhLe74a/es3hIZcQHlbYiTrNl/Qt8fArVu4Z1qR9JTjJ4QHXQ1 kMj2sf5urmimUvuin8roPE6SA8gdai0m2mZk8wRmNkVVFaMHoZ+oKC1yEa2B/r0/BL fTwG1H87iPL62xesByj89b/Yg31IQlZrj5hfrvE5i2WChgxTHyhObjPAJPf6NEY3Zb JOghYPGOFkOzLyrSqk62ulCWWaDDCm3WXMMU0crNXlXNkD7XHLHdW/hQsYumxH44Qa h5OBgBnn8eS6eEUXF4UqyFZEE7l0wuc8zWjkzbTjOOAUOvXJgzx/SdKcFnl5JGuEpS GlPDAzHpQGnxQ== Message-ID: <7a6a28c4-219e-e2aa-ea91-cb0622af62ac@kernel.org> Date: Wed, 6 Sep 2023 16:59:35 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH] ata: ahci: print the lpm policy on boot Content-Language: en-US To: Niklas Cassel Cc: Niklas Cassel , "linux-ide@vger.kernel.org" References: <20230905124909.3334046-1-nks@flawful.org> From: Damien Le Moal Organization: Western Digital Research In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org On 9/6/23 16:54, Niklas Cassel wrote: > Hello Damien, > > On Wed, Sep 06, 2023 at 03:48:02PM +0900, Damien Le Moal wrote: >> On 9/5/23 21:49, Niklas Cassel wrote: >>> From: Niklas Cassel >>> >>> The target LPM policy can be set using either a Kconfig or a kernel module >>> parameter. >>> >>> However, if the board type is set to anything but board_ahci_low_power, >>> then the LPM policy will overridden and set to ATA_LPM_UNKNOWN. >>> >>> Additionally, if the default suspend is suspend to idle, depending on the >>> hardware capabilities of the HBA, ahci_update_initial_lpm_policy() might >>> override the LPM policy to either ATA_LPM_MIN_POWER_WITH_PARTIAL or >>> ATA_LPM_MIN_POWER. >>> >>> All this means that it is very hard to know which LPM policy a user will >>> actually be using on a given system. >>> >>> In order to make it easier to debug LPM related issues, print the LPM >>> policy on boot. >>> >>> One common LPM related issue is that the device fails to link up. >>> Because of that, we cannot add this print to ata_dev_configure(), as that >>> function is only called after a successful link up. Instead, add the info >>> using ata_port_desc(). The port description is printed once during boot. >>> >>> Before changes: >>> ata1: SATA max UDMA/133 abar m524288@0xa5780000 port 0xa5780100 irq 170 >>> ata2: SATA max UDMA/133 abar m524288@0xa5780000 port 0xa5780180 irq 170 >>> >>> After changes: >>> ata1: SATA max UDMA/133 abar m524288@0xa5780000 port 0xa5780100 lpm-pol 4 irq 170 >>> ata2: SATA max UDMA/133 abar m524288@0xa5780000 port 0xa5780180 lpm-pol 4 irq 170 >> >> Looks good, but maybe print the lpm-pol value at the end, after the IRQ number, >> to preserve the beginning of the message as it was before. >> >> Or even better: why not print the LPM modes supported by the port and the target >> lpm policy (lpm-pol) as a new ata_port_info() message right after the port desc >> message ? > > This print already exists: > [ 1.515960] ahci 10000:e0:17.0: AHCI 0001.0301 32 slots 1 ports 6 Gbps 0x1 impl SATA mode > [ 1.515963] ahci 10000:e0:17.0: flags: 64bit ncq sntf pm clo only pio slum part deso sadm sds > > Which prints the capabilities of the HBA. Right. > > The only LPM capability per port, that seems to be able to differ from the > global HBA capability, is PxDEVSLP.DSP: > > " > Device Sleep Present (DSP): If set to ‘1’, the platform supports Device Sleep > on this port. If cleared to ‘0’, the platform does not support Device Sleep on > this port. This bit may only be set to ‘1’ if CAP2.SDS is set to ‘1’. > " > > E.g. on my machine, the HBA has support for DevSleep (supported features print > includes "sds"), but none of the ports seem to have support for DevSleep. > > Would you like PxDEVSLP.DSP printed? We could. > What would be interesting is to be able to know which features the connected > device supports, as e.g. DevSleep needs support both in HBA and the device, > but as the problem is that we usually don't get link up, this is information > is still unknown at this time. Yes. And if the link up is OK, devsleep capability is reported if supported by the device. OK. So let's just keep the lpm-pol message addition, but maybe move it at the end of the message, after the IRQ info. > > > Kind regards, > Niklas > >> >>> >>> Signed-off-by: Niklas Cassel >>> --- >>> drivers/ata/ahci.c | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c >>> index abb5911c9d09..541f6ec7f395 100644 >>> --- a/drivers/ata/ahci.c >>> +++ b/drivers/ata/ahci.c >>> @@ -1898,6 +1898,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) >>> ap->em_message_type = hpriv->em_msg_type; >>> >>> ahci_update_initial_lpm_policy(ap, hpriv); >>> + ata_port_desc(ap, "lpm-pol %d", ap->target_lpm_policy); >>> >>> /* disabled/not-implemented port */ >>> if (!(hpriv->port_map & (1 << i))) >> >> -- >> Damien Le Moal >> Western Digital Research -- Damien Le Moal Western Digital Research