Re: writing to sysfs appears to hang

Mike Anderson (andmike@us.ibm.com)
Fri, 15 Nov 2002 16:47:23 -0800


Paul Larson [plars@linuxtestproject.org] wrote:
> I've been playing with sysfs and notices something odd. If I do this:
> echo 1 > /sys/devices/sys/name
> the process appears to be hung. ^c won't return control to me. If I
> log in on another console though, I can't find it running in the process
> list. All I can do is kill the login process. No kernel errors when I
> do this, just the hung terminal.
>
> -Paul Larson

I repeated your example and in a quick look at the backtrace
the echo is in a loop calling down into sysfs_write_file/dev_attr_store.

I think the problem is that if a device does not have a attribute store
function the return value from dev_attr_store is incorrect.

-andmike

--
Michael Anderson
andmike@us.ibm.com

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