On Sat, Oct 27, 2012 at 6:08 PM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > On 10/27/2012 05:39 PM, Martin Liška wrote: >> Hello, >> I hope being root should not bring any permission issues for the file: >> >> ls -l /sys/bus/iio/devices/iio\:device0/scan_elements/in_illuminance1_en >> *-rw-r--r--* 1 root root 4096 Oct 27 15:54 /sys/bus/iio/devices/iio:device0/scan_elements/in_illuminance1_en >> >> After adding debug print to ii_scan_el_show gives me really *-1* and ***indio_dev->buffer->scan_mask is *1 *and echo >> command settings "1" is processed in *in_scan_el_store* function with ret == 0. > Chase it all the way back and find out where that -1 is coming form. I really can't > guess at the moment. There is only a test_bit and an sprintf if there... Not much scope > really. If it's giving a string containing -1 then it must be from test bit, if returning > -1 from the sprintf. I didn't think test_bit could return an error so we don't check > ret from that. Try to add some printk inside iio code directly, including iio_scan_el_show. You can also build you kernel with debug symbols and trace support, and use ftrace to trace the kernel calls: http://lwn.net/Articles/365835/. -- Corentin Chary http://xf.iksaif.net -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
