From: Guenter Roeck <linux@roeck-us.net>
To: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-hwmon@vger.kernel.org, Jean Delvare <jdelvare@suse.com>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org
Subject: Re: [PATCH 0/1] Summary: hwmon driver for temperature sensors on SATA drives
Date: Mon, 16 Dec 2019 19:57:31 -0800 [thread overview]
Message-ID: <83d528fc-42b7-aa3f-5dd9-a000268da38e@roeck-us.net> (raw)
In-Reply-To: <yq1y2vbhe6i.fsf@oracle.com>
On 12/16/19 6:35 PM, Martin K. Petersen wrote:
>
> Guenter,
>
>> If and when drives are detected which report bad information, such
>> drives can be added to a blacklist without impact on the core SCSI or
>> ATA code. Until that happens, not loading the driver solves the
>> problem on any affected system.
>
> My only concern with that is that we'll have blacklisting several
> places. We already have ATA and SCSI blacklists. If we now add a third
> place, that's going to be a maintenance nightmare.
>
> More on that below.
>
>>> My concerns are wrt. identifying whether SMART data is available for
>>> USB/UAS. I am not too worried about ATA and "real" SCSI (ignoring RAID
>>> controllers that hide the real drives in various ways).
>
> OK, so I spent my weekend tinkering with 15+ years of accumulated USB
> devices. And my conclusion is that no, we can't in any sensible manner,
> support USB storage monitoring in the kernel. There is no heuristic that
> I can find that identifies that "this is a hard drive or an SSD and
> attempting one of the various SMART methods may be safe". As opposed to
> "this is a USB key that's likely to lock up if you try". And that's
> ignoring the drives with USB-ATA bridges that I managed to wedge in my
> attempt at sending down commands.
>
> Even smartmontools is failing to work on a huge part of my vintage
> collection. Thanks to a wide variety of bridges with random, custom
> interfaces.
>
> So my stance on all this is that I'm fine with your general approach for
> ATA. I will post a patch adding the required bits for SCSI. And if a
> device does not implement either of the two standard methods, people
> should use smartmontools.
>
> Wrt. name, since I've added SCSI support, satatemp is a bit of a
> misnomer. drivetemp, maybe? No particular preference.
>
Agreed, if we extend this to SCSI, satatemp is less than perfect.
drivetemp ? disktemp ? I am open to suggestions, with maybe a small
personal preference for disktemp out of those two.
>> The one USB/UAS connected SATA drive I have (a WD passport) reports
>> itself as "WD ", not as "ATA ". I would expect other drives
>> to do the same.
>
> Yes. Most vendors are too fond of their brand names to put "ATA" in
> there. So my suggestion is to relax the heuristic to trigger on the ATA
> Information VPD page only and ignore the name.
>
Fine with me. I wanted to be as restrictive as possible.
> Also, there are some devices that will lock up the way you access that
> VPD page. So a tweak is also required there.
>
Do you have details ? Do I need to add a call to scsi_device_supports_vpd(),
maybe ?
> To avoid the multiple blacklists and heuristic collections my suggestion
> is that I introduce a helper function in SCSI (based on what I did in
> the disk driver) that can be called to identify whether something is an
> ATA device. And then the hwmon driver can call that and we can keep the
> heuristics in one place.
>
> If a device turns out to be problematic wrt. getting the ATA VPD for the
> purpose of SMART, for instance, it will also need to be blacklisted for
> other reasons in SCSI. So I would really like to keep the heuristics in
> one place.
>
Fine with me. My only concern is that I don't want the driver to disappear
into nowhere-land (again).
Thanks,
Guenter
next prev parent reply other threads:[~2019-12-17 3:57 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-09 5:21 [PATCH 0/1] Summary: hwmon driver for temperature sensors on SATA drives Guenter Roeck
2019-12-09 5:21 ` [PATCH 1/1] hwmon: Driver " Guenter Roeck
2019-12-09 5:28 ` Randy Dunlap
2019-12-09 6:00 ` Guenter Roeck
2019-12-09 17:08 ` Bart Van Assche
2019-12-09 19:20 ` Guenter Roeck
2019-12-10 16:10 ` Bart Van Assche
2019-12-12 22:33 ` Linus Walleij
2019-12-12 23:21 ` Martin K. Petersen
2019-12-13 4:18 ` Guenter Roeck
2019-12-17 2:47 ` Martin K. Petersen
2019-12-17 4:20 ` Guenter Roeck
2019-12-18 3:39 ` Martin K. Petersen
2019-12-11 4:08 ` [PATCH 0/1] Summary: hwmon driver " Martin K. Petersen
2019-12-11 5:57 ` Guenter Roeck
2019-12-17 2:35 ` Martin K. Petersen
2019-12-17 3:57 ` Guenter Roeck [this message]
2019-12-17 5:50 ` Damien Le Moal
2019-12-17 15:47 ` Guenter Roeck
2019-12-18 3:42 ` Martin K. Petersen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=83d528fc-42b7-aa3f-5dd9-a000268da38e@roeck-us.net \
--to=linux@roeck-us.net \
--cc=jdelvare@suse.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-hwmon@vger.kernel.org \
--cc=linux-ide@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=martin.petersen@oracle.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).