Add timout loop after exporting the PWM pin.

This gives udev time to respond to the device event. Without this,
the subsequent attempts to modify pin properties will fail when
depending on udev rules to apply new user permissions.

This code is essentially copied from python-periphery, as was most
of this file (both MIT licenced). Although it appears sergeev added
this loop recently, compared to when this code was originally cloned.

diff --git a/src/adafruit_blinka/microcontroller/generic_linux/sysfs_pwmout.py b/src/adafruit_blinka/microcontroller/generic_linux/sysfs_pwmout.py
index 1344f4faf9216ee6e16dedc347886e22f9b4fd22..2d58621c010686c3ce389e170eb627e3f90e5500 100644 (file)
--- a/src/adafruit_blinka/microcontroller/generic_linux/sysfs_pwmout.py
+++ b/src/adafruit_blinka/microcontroller/generic_linux/sysfs_pwmout.py
@@ -32,16 +32,6 @@ class PWMOut:
     # Delay between check for scucessful PWM export on open (100ms)
     PWM_STAT_DELAY = 0.1
 
-    # Number of retries to check for successful PWM export on open
-    PWM_STAT_RETRIES = 10
-    # Delay between check for scucessful PWM export on open (100ms)
-    PWM_STAT_DELAY = 0.1
-
-    # Number of retries to check for successful PWM export on open
-    PWM_STAT_RETRIES = 10
-    # Delay between check for scucessful PWM export on open (100ms)
-    PWM_STAT_DELAY = 0.1
-
     # Sysfs paths
     _sysfs_path = "/sys/class/pwm/"
     _channel_path = "pwmchip{}"