Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752635AbbHCDCT (ORCPT ); Sun, 2 Aug 2015 23:02:19 -0400 Received: from mail-la0-f42.google.com ([209.85.215.42]:33511 "EHLO mail-la0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752252AbbHCDCR convert rfc822-to-8bit (ORCPT ); Sun, 2 Aug 2015 23:02:17 -0400 MIME-Version: 1.0 In-Reply-To: <201508021108.52978@pali> References: <201412232051.07067@pali> <201508012209.27974@pali> <201508021108.52978@pali> Date: Sun, 2 Aug 2015 21:02:15 -0600 Message-ID: Subject: Re: linux: sata_nv: adma support From: Robert Hancock To: =?UTF-8?Q?Pali_Roh=C3=A1r?= Cc: Jeff Garzik , Robert Hancock , Tejun Heo , "linux-ide@vger.kernel.org" , linux-kernel Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5836 Lines: 146 On Sun, Aug 2, 2015 at 3:08 AM, Pali Rohár wrote: > On Sunday 02 August 2015 03:45:32 Robert Hancock wrote: >> On Sat, Aug 1, 2015 at 2:09 PM, Pali Rohár >> wrote: >> > On Thursday 25 December 2014 07:22:13 Robert Hancock wrote: >> >> On Tue, Dec 23, 2014 at 1:51 PM, Pali Rohár >> >> >> >> wrote: >> >> > Hello, >> >> > >> >> > I have nvidia nforce4 motherboard with nvidia sata controller: >> >> > >> >> > 00:07.0 IDE interface [0101]: NVIDIA Corporation CK804 Serial >> >> > ATA Controller [10de:0054] (rev f3) >> >> > 00:08.0 IDE interface [0101]: NVIDIA Corporation CK804 Serial >> >> > ATA Controller [10de:0055] (rev f3) >> >> > >> >> > I manually enabled adma mode (which is disabled by default) by >> >> > adding sata_nv.adma=1 to grub cmdline. In git history I found >> >> > that enabling adma mode includes NCQ support and reduced CPU >> >> > overhead. It looks like adma mode is working, but at every boot >> >> > I see one same error message in dmesg: >> >> > >> >> > [ 16.823514] ata1.00: exception Emask 0x1 SAct 0x0 SErr 0x0 >> >> > action 0x0 >> >> > [ 16.823520] ata1.00: CPB resp_flags 0x11: , CMD error >> >> > [ 16.823524] ata1.00: failed command: SET FEATURES >> >> > [ 16.823530] ata1.00: cmd ef/05:fe:00:00:00/00:00:00:00:00/40 >> >> > tag 16 >> >> > [ 16.823530] res 51/04:fe:00:00:00/00:00:00:00:00/40 >> >> > Emask 0x1 (device error) >> >> > [ 16.823533] ata1.00: status: { DRDY ERR } >> >> > [ 16.823535] ata1.00: error: { ABRT } >> >> > >> >> > When adma is disabled then this error message is not generated. >> >> >> >> It looks like something is trying to issue a command to disable >> >> APM power management on the drive, and the command fails (likely >> >> because it doesn't support that command). I'm not sure where that >> >> would be coming from - I'm pretty sure the kernel doesn't issue >> >> that command itself. Something that's part of your distro >> >> perhaps? >> >> >> >> I don't know why it would only be failing in ADMA mode either, >> >> though depending on where the command is coming from, maybe it's >> >> not being issued otherwise for some reason? >> >> >> >> > What does that error message means? It is critical? What is that >> >> > command SET FEATURES doing? Are there any problems with adma >> >> > mode on nforce4 motherboards? Because I did not see any >> >> > problems (except that one error message). >> >> > >> >> > -- >> >> > Pali Rohár >> >> > pali.rohar@gmail.com >> > >> > Hello, >> > >> > now after long time I did more investigation and that error is >> > reported for every connected HDD. I identified that it comes from >> > udev script >> > >> > /lib/udev/rules.d/85-hdparm.rules >> > >> > which just call script /lib/udev/hdparm for every one connected >> > HDD. >> > >> > Script /lib/udev/hdparm just call: >> > /sbin/hdparm -B254 $DRIVE >> > >> > And that -B254 cause above error message in dmesg log. Output from >> > >> > hdparm is: >> > /dev/sda: >> > setting Advanced Power Management level to 0xfe (254) >> > APM_level = not supported >> > >> > Any idea why in ADMA mode it cause above error (APM unsupported) >> > and in non ADMA mode it is working fine? Maybe APM ATA commands >> > should not be sent via ADMA? >> > >> > Here is another output: >> > $ sudo hdparm -I /dev/sda | grep -i power >> > >> > * Power Management feature set >> > >> > Power-Up In Standby feature set >> > >> > * SET_FEATURES required to spinup after power up >> > * Host-initiated interface power management >> >> The "set features" command is a non-data command so based on our >> current knowledge, it should work in ADMA mode. However, these NVIDIA >> SATAs are black boxes, and rather buggy ones at that, so it's >> possible there's an unknown issue there. >> > > Maybe I should note that hdparm -I did not generated any error message. > I post is here because it show "Power Management feature set" is > supported by HDD. This indicate that HDD supports -B (APM) command, > right? As far as I know, yes. > >> The easiest way to test that would be to take out the condition check >> for qc->tf.protocol == ATA_PROT_NODATA in nv_adma_use_reg_mode in >> drivers/ata/sata_nv.c. That would force it to disable ADMA for all >> non-data commands. >> > > Ok, as now I have just SSH access to that machine, I will do kernel > patching later (when I have physical access to it). > >> I really don't know why Ubuntu is disabling APM on all drives on >> bootup however. Especially for laptops, that seems like a silly thing >> to do explicitly. Sounds like one of the silly things Ubuntu is known >> to do without consulting people. > > Looks like this comes from upstream udev/systemd project :-( Anyway, for > laptops on battery ubuntu has another set of scripts which turn on APM > (based on connected/disconnected AC adapter). There's no such scripts in Fedora, so either they removed it, or it's something that either Debian or Ubuntu has added in. > > That udev script which turn off APM is called when any disk is attached > to system (so at boot time it is called for every one disk). > > Now I just masked that udev script and it is no longer called... > > Anyway if I call hdparm -B /dev/sda I get output: > > APM_level = not supported > > And important is that there is no error message in dmesg. I get it only > if I call hdparm -B with parameter (set option). But APM should be > supported, right? Does the get command work without ADMA enabled? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/