From: Greg KH <gregkh@linuxfoundation.org>
To: Borislav Petkov <bp@alien8.de>,
Mauro Carvalho Chehab <mchehab@redhat.com>,
balbi@ti.com,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@redhat.com>,
JBottomley@parallels.com, linux-scsi@vger.kernel.org,
davem@davemloft.net, netdev@vger.kernel.org,
Doug Thompson <dougthompson@xmission.com>,
linux-edac@vger.kernel.org, rjw@sisk.pl,
linux-pm@vger.kernel.org
Subject: Re: SYSFS "errors"
Date: Mon, 18 Feb 2013 14:26:18 -0800 [thread overview]
Message-ID: <20130218222618.GA21818@kroah.com> (raw)
In-Reply-To: <20130218221306.GA21493@pd.tnic>
On Mon, Feb 18, 2013 at 11:13:06PM +0100, Borislav Petkov wrote:
> On Mon, Feb 18, 2013 at 01:54:34PM -0800, Greg KH wrote:
> > Because sysfs is "one value per file" the lack of a file showing up
> > shouldn't cause any userspace tools any problems, that is why we did
> > things this way.
> >
> > But, of course, userspace programmers do know how to mess things up...
>
> How about what I proposed earlier to Felipe:
>
> --
> diff --git a/drivers/edac/edac_mc_sysfs.c b/drivers/edac/edac_mc_sysfs.c
> index 0ca1ca71157f..d2eef76d1d46 100644
> --- a/drivers/edac/edac_mc_sysfs.c
> +++ b/drivers/edac/edac_mc_sysfs.c
> @@ -704,7 +704,7 @@ static ssize_t mci_sdram_scrub_rate_show(struct device *dev,
> int bandwidth = 0;
>
> if (!mci->get_sdram_scrub_rate)
> - return -ENODEV;
> + return sprintf(data, "N/A");
>
> bandwidth = mci->get_sdram_scrub_rate(mci);
> if (bandwidth < 0) {
>
> --
>
> Would that hurt the sysfs policy? In this case we *can* read the file
> and it correctly tells us that scrub rate reading is not supported
> instead of having a number there.
>
> Hmm.
I don't know, it depends on if userspace can handle this properly or
not. What tools rely on this sysfs file? WHat happens when they get a
non-number in the file?
thanks,
greg k-h
next prev parent reply other threads:[~2013-02-18 22:26 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-18 15:33 SYSFS "errors" Felipe Balbi
2013-02-18 15:50 ` Greg KH
2013-02-18 15:52 ` Felipe Balbi
2013-02-18 17:13 ` Greg KH
2013-02-18 17:27 ` Felipe Balbi
2013-02-18 17:45 ` Borislav Petkov
2013-02-18 18:47 ` Felipe Balbi
2013-02-18 19:40 ` Borislav Petkov
2013-02-18 20:04 ` Felipe Balbi
2013-02-18 17:49 ` Greg KH
2013-02-18 18:46 ` Felipe Balbi
2013-02-18 19:46 ` Mauro Carvalho Chehab
2013-02-18 20:05 ` Felipe Balbi
2013-02-18 21:47 ` Mauro Carvalho Chehab
2013-02-18 21:54 ` Greg KH
2013-02-18 22:13 ` Borislav Petkov
2013-02-18 22:26 ` Greg KH [this message]
2013-02-18 22:44 ` Borislav Petkov
2013-02-19 10:03 ` Mauro Carvalho Chehab
2013-02-19 10:11 ` Felipe Balbi
2013-02-19 11:11 ` Mauro Carvalho Chehab
2013-02-19 11:43 ` Borislav Petkov
2013-02-19 12:16 ` Mauro Carvalho Chehab
2013-02-19 12:35 ` Borislav Petkov
2013-02-19 12:46 ` Mauro Carvalho Chehab
2013-02-19 13:06 ` Borislav Petkov
2013-02-19 13:15 ` Felipe Balbi
2013-02-19 13:28 ` Borislav Petkov
2013-02-19 13:38 ` Felipe Balbi
2013-02-19 13:50 ` Mauro Carvalho Chehab
2013-02-19 13:55 ` Borislav Petkov
2013-02-19 13:50 ` Borislav Petkov
2013-02-19 13:58 ` Hannes Reinecke
2013-02-19 14:10 ` Borislav Petkov
2013-02-19 14:14 ` Mauro Carvalho Chehab
2013-02-19 14:19 ` Felipe Balbi
2013-02-19 14:35 ` Mauro Carvalho Chehab
2013-02-19 14:50 ` Borislav Petkov
2013-02-19 14:53 ` Felipe Balbi
2013-02-19 13:42 ` Mauro Carvalho Chehab
2013-02-18 21:48 ` Alan Stern
2013-02-18 21:57 ` Felipe Balbi
2013-02-19 7:41 ` Alexander Stein
2013-02-19 10:12 ` Felipe Balbi
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