Wait until GPIO file appears on the /sys filesystem (issue #36)

[olegantonyan]

Fixed issue #36 with non-root access to GPIO

[pdp7]

@olegantonyan There have been several PRs merged, most recently #108. Could you please check to see if this is an issue and that your PR resolves the issue?

[olegantonyan]

It's been so long ago I don't remember the actual problem :) I need a bit more time to reproduce it.
But as far as I can see from the source code there are no changes related to this issue. Results of gpio_export(), gpio_set_direction() and gpio_set_value() are ignored and there is a chance that one of them will be not successful because of timings (sysfs file is not created yet)

[pdp7]

@olegantonyan Thanks for the update. I'll try out this fix from your branch so that I can better understand the issue.

[pdp7]

@olegantonyan thanks for the pull request. Unfortuantely, it now conflicts after recent merges. Could you please resolve the conflict so that I can test this PR?

[olegantonyan]

This should probably work :)

[pdp7]

Tested OK on:

3.8.13-bone80

• BeagleBoard.org Debian Image 2016-06-15
• Debian 7.11

root@beaglebone:~/olegantonyan-bbio# pytest
platform linux2 -- Python 2.7.3, pytest-3.0.3, py-1.4.31, pluggy-0.4.0
rootdir: /root/olegantonyan-bbio, inifile: 
collected 57 items 

test/test_adc.py ......
test/test_gpio_input.py ..
test/test_gpio_output.py ......
test/test_gpio_setup.py ..........
test/test_led.py ..
test/test_pwm_setup.py ..........................
test/test_spi.py ..
test/test_uart.py ...

57 passed in 46.69 seconds

4.1.30-ti-r69

• BeagleBoard.org Debian Image 2016-08-14
• Debian 8.6

root@beaglebone:~/olegantonyan-bbio# pytest
platform linux2 -- Python 2.7.9, pytest-3.0.3, py-1.4.31, pluggy-0.4.0
rootdir: /root/olegantonyan-bbio, inifile: 
collected 57 items 

test/test_adc.py ......
test/test_gpio_input.py ..
test/test_gpio_output.py ......
test/test_gpio_setup.py ..........
test/test_led.py ..
test/test_pwm_setup.py ..........................
test/test_spi.py ..
test/test_uart.py ...
57 passed in 46.20 seconds

[pdp7]

@olegantonyan thanks for your efforts!