Ubuntu 24.04.2 LTS にTVチューナー PX-W3PE4 のドライバをインストールする

この度重い腰を上げて自宅のUbuntuサーバーを 22.04.5 LTS から 24.04.2 LTS にアップデートしたところ、刺していたTVチューナーを認識しなくなった。

$ ls /dev/px*
(ドライバファイルが表示されない)

アップデートに伴ってチューナーのドライバが削除されていたっぽいので、以下の非公式ドライバをインストールしようとした。
https://github.com/nns779/px4_drv

READMEにある手順通りに進めると、ドライバのビルドでエラーを吐いた。

'revision.h' was updated.
make[1]: Entering directory '/usr/src/linux-headers-6.8.0-59-generic'
warning: the compiler differs from the one used to build the kernel
  The kernel was built by: x86_64-linux-gnu-gcc-13 (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0
  You are using:           gcc-13 (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0
  CC [M]  /home/mana/tmp/px4_drv/driver/driver_module.o
  CC [M]  /home/mana/tmp/px4_drv/driver/ptx_chrdev.o
/home/mana/tmp/px4_drv/driver/ptx_chrdev.c: In function ‘ptx_chrdev_context_create’:
/home/mana/tmp/px4_drv/driver/ptx_chrdev.c:569:9: error: implicit declaration of function ‘strlcpy’; did you mean ‘strscpy’? [-Werror=implicit-function-declaration]
  569 |         strlcpy(ctx->devname, devname, sizeof(ctx->devname));
      |         ^~~~~~~
      |         strscpy
In file included from ./arch/x86/include/asm/mem_encrypt.h:15,
                 from ./include/linux/mem_encrypt.h:17,
                 from ./arch/x86/include/asm/processor-flags.h:6,
                 from ./arch/x86/include/asm/irqflags.h:5,
                 from ./include/linux/irqflags.h:18,
                 from ./include/linux/spinlock.h:59,
                 from ./include/linux/kref.h:16,
                 from /home/mana/tmp/px4_drv/driver/ptx_chrdev.h:13,
                 from /home/mana/tmp/px4_drv/driver/ptx_chrdev.c:9:
./include/linux/init.h:188:22: error: passing argument 1 of ‘class_create’ from incompatible pointer type [-Werror=incompatible-pointer-types]
  188 | #define THIS_MODULE (&__this_module)
      |                     ~^~~~~~~~~~~~~~~
      |                      |
      |                      struct module *
/home/mana/tmp/px4_drv/driver/ptx_chrdev.c:573:35: note: in expansion of macro ‘THIS_MODULE’
  573 |         ctx->class = class_create(THIS_MODULE, name);
      |                                   ^~~~~~~~~~~
In file included from ./include/linux/device.h:31,
                 from ./include/linux/cdev.h:8,
                 from /home/mana/tmp/px4_drv/driver/ptx_chrdev.h:16:
./include/linux/device/class.h:228:54: note: expected ‘const char *’ but argument is of type ‘struct module *’
  228 | struct class * __must_check class_create(const char *name);
      |                                          ~~~~~~~~~~~~^~~~
/home/mana/tmp/px4_drv/driver/ptx_chrdev.c:573:22: error: too many arguments to function ‘class_create’
  573 |         ctx->class = class_create(THIS_MODULE, name);
      |                      ^~~~~~~~~~~~
./include/linux/device/class.h:228:29: note: declared here
  228 | struct class * __must_check class_create(const char *name);
      |                             ^~~~~~~~~~~~
/home/mana/tmp/px4_drv/driver/ptx_chrdev.c: At top level:
/home/mana/tmp/px4_drv/driver/ptx_chrdev.c:727:5: warning: no previous prototype for ‘ptx_chrdev_context_reserve’ [-Wmissing-prototypes]
  727 | int ptx_chrdev_context_reserve(struct ptx_chrdev_context *chrdev_ctx,
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
make[3]: *** [scripts/Makefile.build:243: /home/mana/tmp/px4_drv/driver/ptx_chrdev.o] Error 1
make[2]: *** [/usr/src/linux-headers-6.8.0-59-generic/Makefile:1925: /home/mana/tmp/px4_drv/driver] Error 2
make[1]: *** [Makefile:240: __sub-make] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-6.8.0-59-generic'
make: *** [Makefile:19: px4_drv.ko] Error 2

どうやら新旧のカーネル間で関数が無くなっていたり、仕様の違いがあるよう。
もうリポジトリはメンテされていなさそうなので、forkして自分でパッチした。

From e76c6aa45717cc17725c8c1cecba6951a7bf5b6d Mon Sep 17 00:00:00 2001
From: s4kr4 <[e-mail]>
Date: Tue, 13 May 2025 23:49:50 +0900
Subject: [PATCH] Update for Linux Kernel 6.8 or later

---
 driver/ptx_chrdev.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/driver/ptx_chrdev.c b/driver/ptx_chrdev.c
index dec1cee..3d56dea 100644
--- a/driver/ptx_chrdev.c
+++ b/driver/ptx_chrdev.c
@@ -566,11 +566,11 @@ int ptx_chrdev_context_create(const char *name, const char *devname,
 		return -ENOMEM;
 
 	mutex_init(&ctx->lock);
-	strlcpy(ctx->devname, devname, sizeof(ctx->devname));
+	strscpy(ctx->devname, devname, sizeof(ctx->devname));
 
 	INIT_LIST_HEAD(&ctx->group_list);
 
-	ctx->class = class_create(THIS_MODULE, name);
+	ctx->class = class_create(name);
 	if (IS_ERR(ctx->class)) {
 		pr_err("ptx_chrdev_context_create: class_create(\"%s\") failed.\n",
 		       name);

forkリポジトリは以下
https://github.com/s4kr4/px4_drv

無事ビルドが通ったのでそのまま make install し、無事ドライバの動作を確認できた。

$ ls /dev/px*
/dev/px4video0  /dev/px4video1  /dev/px4video2  /dev/px4video3