Re: SYSFS "errors"

From: Borislav Petkov <bp@alien8.de>
To: Felipe Balbi <balbi@ti.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>,
	Greg KH <gregkh@linuxfoundation.org>,
	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: Tue, 19 Feb 2013 14:50:56 +0100	[thread overview]
Message-ID: <20130219135056.GH26623@pd.tnic> (raw)
In-Reply-To: <20130219133809.GA4390@arwen.pp.htv.fi>

On Tue, Feb 19, 2013 at 03:38:09PM +0200, Felipe Balbi wrote:
> because changing the permission will cause the same issue:

Actually, I take that back. Mauro's patch will already create the file
anyway:

	if (mci->set_sdram_scrub_rate || mci->get_sdram_scrub_rate)

Adjusting the permissions is simply the last missing piece to this patch
to make the interface to userspace 100% coherent.

--
From: Mauro Carvalho Chehab <mchehab@redhat.com>
Date: Tue, 19 Feb 2013 09:16:10 -0300
Subject: [PATCH] EDAC: only create sdram_scrub_rate where supported

Currently, sdram_scrub_rate sysfs node is created even if the device
doesn't support get/set the scub rate. Change the logic to only
create this device node when the operation is supported.

If only read or only write is supported, it will keep returning -ENODEV
just like before.

Reported-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---
 drivers/edac/edac_mc_sysfs.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/edac/edac_mc_sysfs.c b/drivers/edac/edac_mc_sysfs.c
index 0ca1ca71157f..5a788e60ff67 100644
--- a/drivers/edac/edac_mc_sysfs.c
+++ b/drivers/edac/edac_mc_sysfs.c
@@ -7,7 +7,7 @@
  *
  * Written Doug Thompson <norsk5@xmission.com> www.softwarebitmaker.com
  *
- * (c) 2012 - Mauro Carvalho Chehab <mchehab@redhat.com>
+ * (c) 2012-2013 - Mauro Carvalho Chehab <mchehab@redhat.com>
  *	The entire API were re-written, and ported to use struct device
  *
  */
@@ -878,7 +878,6 @@ static struct attribute *mci_attrs[] = {
 	&dev_attr_ce_noinfo_count.attr,
 	&dev_attr_ue_count.attr,
 	&dev_attr_ce_count.attr,
-	&dev_attr_sdram_scrub_rate.attr,
 	&dev_attr_max_location.attr,
 	NULL
 };
@@ -1012,6 +1011,23 @@ int edac_create_sysfs_mci_device(struct mem_ctl_info *mci)
 		return err;
 	}
 
+	if (mci->set_sdram_scrub_rate || mci->get_sdram_scrub_rate) {
+		umode_t mode = 0;
+
+		if (mci->get_sdram_scrub_rate)
+			mode = S_IRUGO;
+
+		if (mci->set_sdram_scrub_rate)
+			mode |= S_IWUSR;
+
+		dev_attr_sdram_scrub_rate.attr.mode = mode;
+
+		err = device_create_file(&mci->dev, &dev_attr_sdram_scrub_rate);
+		if (err) {
+			edac_dbg(1, "failure: create sdram_scrub_rate\n");
+			goto fail2;
+		}
+	}
 	/*
 	 * Create the dimm/rank devices
 	 */
@@ -1056,6 +1072,7 @@ fail:
 			continue;
 		device_unregister(&dimm->dev);
 	}
+fail2:
 	device_unregister(&mci->dev);
 	bus_unregister(&mci->bus);
 	kfree(mci->bus.name);
-- 
1.8.1.3.535.ga923c31


-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--
