I used a pr_debug and printk KERN_INFO ,before my original email , to verify they weren't being called. On Apr 17, 2017 1:43 PM, <valdis.kletnieks@vt.edu> 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");
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..)