Fix for 6.1.0-15-amd64 error: implicit declaration of function ‘pran…

[younicoin]

Hello! I used your driver as it works so good, very reliable. But upgrading system got error because of it.

apt upgrade
The following packages were automatically installed and are no longer required:
  linux-headers-6.1.0-12-amd64 linux-headers-6.1.0-12-common
  linux-image-6.1.0-12-amd64

Building module:
Cleaning build area...
'make' KVER=6.1.0-15-amd64...............(bad exit status: 2)
Error! Bad return status for module build on kernel: 6.1.0-15-amd64 (x86_64)
Consult /var/lib/dkms/rtl8821CU/5.4.1/build/make.log for more information.
Error! One or more modules failed to install during autoinstall.
Refer to previous errors for more information.
dkms: autoinstall for kernel: 6.1.0-15-amd64 failed!
run-parts: /etc/kernel/postinst.d/dkms exited with return code 11
dpkg: error processing package linux-image-6.1.0-15-amd64 (--configure):
 installed linux-image-6.1.0-15-amd64 package post-installation script subproces
s returned error exit status 1
dpkg: dependency problems prevent configuration of linux-headers-amd64:
 linux-headers-amd64 depends on linux-headers-6.1.0-15-amd64 (= 6.1.66-1); howev
er:
  Package linux-headers-6.1.0-15-amd64 is not configured yet.

  Package linux-headers-6.1.0-15-amd64 is not configured yet.

dpkg: error processing package linux-headers-amd64 (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of linux-image-amd64:
 linux-image-amd64 depends on linux-image-6.1.0-15-amd64 (= 6.1.66-1); however:
  Package linux-image-6.1.0-15-amd64 is not configured yet.

dpkg: error processing package linux-image-amd64 (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 linux-headers-6.1.0-15-amd64
 linux-image-6.1.0-15-amd64
 linux-headers-amd64
 linux-image-amd64
E: Sub-process /usr/bin/dpkg returned an error code (1)


vim /var/lib/dkms/rtl8821CU/5.4.1/build/make.log
/var/lib/dkms/rtl8821CU/5.4.1/build/os_dep/osdep_service.c: In function ‘rtw_change_ifname’:
/var/lib/dkms/rtl8821CU/5.4.1/build/os_dep/osdep_service.c:2494:28: warning: passing argument 1 of ‘_rtw_memcpy’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
 2494 |         _rtw_memcpy(pnetdev->dev_addr, adapter_mac_addr(padapter), ETH_ALEN);
      |                     ~~~~~~~^~~~~~~~~~
/var/lib/dkms/rtl8821CU/5.4.1/build/os_dep/osdep_service.c:925:24: note: expected ‘void *’ but argument is of type ‘const unsigned char *’
  925 | void _rtw_memcpy(void *dst, const void *src, u32 sz)
      |                  ~~~~~~^~~
/var/lib/dkms/rtl8821CU/5.4.1/build/os_dep/osdep_service.c: In function ‘rtw_random32’:
/var/lib/dkms/rtl8821CU/5.4.1/build/os_dep/osdep_service.c:2618:16: error: implicit declaration of function ‘prandom_u32’; did you mean ‘prandom_u32_max’? [-Werror=implicit-function-declaration]
 2618 |         return prandom_u32();
      |                ^~~~~~~~~~~
      |                prandom_u32_max
cc1: some warnings being treated as errors

So I just followed recommendation from error and now have no issue on my system.

lsb_release -a
No LSB modules are available.
Distributor ID:	Devuan
Description:	Devuan GNU/Linux 5 (daedalus)
Release:	5
Codename:	daedalus

uname -a
Linux devuan 6.1.0-15-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.66-1 (2023-12-09) x86_64 GNU/Linux

gcc --version
gcc (Debian 12.2.0-14) 12.2.0

With my fix have no issues while upgrading.