attempted fix for country code issues

8821cu.conf

@@ -8,7 +8,7 @@
 # documentation.
 #
 # Edit the following line to change, add or delete options:
-options 8821cu rtw_drv_log_level=0 rtw_led_ctrl=1 rtw_vht_enable=1 rtw_power_mgnt=1 rtw_dfs_region_domain=0
+options 8821cu rtw_drv_log_level=0 rtw_led_ctrl=1 rtw_vht_enable=1 rtw_power_mgnt=1
 #
 # After editing is complete, save this file (if using nano: Ctrl + x, y, Enter)
 # and reboot to activate the changes.
@@ -65,7 +65,7 @@ options 8821cu rtw_drv_log_level=0 rtw_led_ctrl=1 rtw_vht_enable=1 rtw_power_mgn
 #
 # -----
 #
-# Country Code options ( rtw_country_code )
+# ISO 3166-1 alpha-2 Country Code options ( rtw_country_code )
 #
 # Note: Allows the Country Code to be set in cases where it is unable to
 # be obtained from the operating system.
@@ -75,6 +75,8 @@ options 8821cu rtw_drv_log_level=0 rtw_led_ctrl=1 rtw_vht_enable=1 rtw_power_mgn
 # Example for Norway: rtw_country_code=NO
 # Example for Kuwait: rtw_country_code=KW
 # Example for Taiwan: rtw_country_code=TW
+#
+# ISO 3166-1 alpha-2 codes: https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2
 # 
 # -----
 #

README.md

@@ -204,6 +204,24 @@ install this driver and, after a reboot, the driver is not working, you
 can go into the BIOS and temporarily turn secure boot off to see if
 secure boot is the problem.
 
+Please ensure the ISO 3166-1 alpha-2 Country Code is set in your Linux distro.
+If it is not set, you will likely have problems accessing some channels, especially
+5 Ghz and 6 GHz channels. To set your Country Code:
+
+```
+iw reg set US
+```
+
+If you are not in the US, please use the country code for your country. See:
+
+ISO 3166-1 alpha-2 codes: https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2
+
+To check if your country code is properly set:
+
+```
+iw reg get
+```
+
 ### Installation Steps
 
 Note: The installation instructions are for the novice user. Experienced users are
@@ -258,6 +276,10 @@ sudo reboot
 
 #### Step 3: Install the required packages (select the option for the OS you are using)
 
+Note: If your Linux distro does not fall into one of options listed
+below, you will need to research how to properly setup up the development
+environment for your system.
+
 - Option for Raspberry Pi OS (ARM/ARM64)
 
 ```

include/autoconf.h

@@ -21,6 +21,7 @@
 #define AUTOCONF_INCLUDED
 #define RTL871X_MODULE_NAME "8821CU"
 #define DRV_NAME "rtl8821cu"
+#define CONFIG_REGD_SRC_FROM_OS
 
 /* Set CONFIG_RTL8821C from Makefile */
 #ifndef CONFIG_RTL8821C