From mboxrd@z Thu Jan 1 00:00:00 1970 From: me@tobin.cc (Tobin C. Harding) Date: Tue, 18 Apr 2017 10:05:17 +1000 Subject: Problems with adding a sysfs file In-Reply-To: References: <24220.1492461838@turing-police.cc.vt.edu> Message-ID: <20170418000517.GB745@eros> To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org On Mon, Apr 17, 2017 at 02:04:48PM -0700, Abhishek Bhardwaj wrote: > I used a pr_debug and printk KERN_INFO ,before my original email , to > verify they weren't being called. You will have more success on kernel mailing lists if you do not top post as you have done :) > On Apr 17, 2017 1:43 PM, wrote: > > > On Mon, 17 Apr 2017 01:17:08 -0700, Abhishek Bhardwaj said: > > > I followed this link to add a sysfs file > > > http://kroah.com/log/blog/2013/06/26/how-to-create-a- > > sysfs-file-correctly/ > > > . > > > > > > I set the driver.groups field and declared the attribute and attribute > > > groups required by the sysfs file. When I boot my kernel I see the > > > file but my store and show handlers don't get called when I try to cat > > > or echo to the file. Is there any step I'm missing ?. > > > > The traditional way to start debugging this is to add a line at the > > beginning > > of your show and store routines: > > > > printk(KERN_DEBUG "Now in our special sysfs show routine\n"); You could have put your response here, that way readers would have a reference to you comment. > > and see if it shows up in your dmesg or not. If not, your routine > > is probably not being called. If it is, the problem is in the routine. > > > > (You'd be surprised how often people say their routine isn't getting > > called, > > when it in fact is, or vice versa..) > > Good luck, Tobin.