Re: SYSFS "errors"

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.

-- 
Regards/Gruss,
    Boris.

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