fix character subsystem initialisation panic

PATCH In review James Bottomley 2 participants 2 messages Jun 8, 2003

Subsystems (4)

TTY layer and serial drivers Char and misc drivers Arm/actions semi architecture Random number driver

lore

Share & tools

lore

James Bottomley

author

2003-06-08 17:21 UTC #0 lore raw

PATCH 1/1 fix character subsystem initialisation panic

In 2.5.70 bk latest, I'm getting a panic related to character device initialisation. The problem seems to be that the new sysfs entries for character devices require that everything now have a properly initialised parent. However, the character subsystem is set up in drivers/char/mem.c as

__initcall(chr_dev_init);

However, __initcall() is the same priority as module_init(), so whether character devices are initialised before their required subsystem depends purely on link ordering (on parisc, we initialise devices/parisc before everything else, so it is panicing reliably with this).

I think the fix is to convert the __initcall to subsys_initcall (patch attached). The patch allows parisc to boot properly now.

James

===== drivers/char/mem.c 1.39 vs edited =====

drivers/char/mem.c +1 -1

@@ -713,4 +713,4 @@
 	return 0;
 }
 
-__initcall(chr_dev_init);
+subsys_initcall(chr_dev_init);

Christoph Hellwig

2003-06-08 18:30 UTC #1 lore raw

Quoted 8 lines · James Bottomley

In 2.5.70 bk latest, I'm getting a panic related to character device initialisation. The problem seems to be that the new sysfs entries for character devices require that everything now have a properly initialised parent. However, the character subsystem is set up in drivers/char/mem.c as
__initcall(chr_dev_init);

Quoted 7 lines

However, __initcall() is the same priority as module_init(), so whether character devices are initialised before their required subsystem depends purely on link ordering (on parisc, we initialise devices/parisc before everything else, so it is panicing reliably with this).
I think the fix is to convert the __initcall to subsys_initcall (patch attached). The patch allows parisc to boot properly now.

This means that all the drivers initialized from chr_dev_init are also at subsystem level now which doesn't seem to break something (yet) but still is v ery confusing. This patch converts all of them (except fbmem_init which is in a different directory so we could get link order problems) to module_init.

drivers/char/mem.c +0 -9

@@ -698,17 +698,8 @@
 				S_IFCHR | devlist[i].mode, devlist[i].name);
 	}
 	
-	rand_initialize();
 #if defined (CONFIG_FB)
 	fbmem_init();
-#endif
-	tty_init();
-#ifdef CONFIG_M68K_PRINTER
-	lp_m68k_init();
-#endif
-	misc_init();
-#ifdef CONFIG_FTAPE
-	ftape_init();
 #endif
 	return 0;
 }

drivers/char/misc.c +2 -1

@@ -244,7 +244,7 @@
 EXPORT_SYMBOL(misc_register);
 EXPORT_SYMBOL(misc_deregister);
 
-int __init misc_init(void)
+static int __init misc_init(void)
 {
 	create_proc_read_entry("misc", 0, 0, misc_read_proc, NULL);
 #ifdef CONFIG_MVME16x

@@ -281,3 +281,4 @@
 	}
 	return 0;
 }
+module_init(misc_init);

drivers/char/random.c +2 -1

@@ -1420,7 +1420,7 @@
 	}
 }
 
-void __init rand_initialize(void)
+static void __init rand_initialize(void)
 {
 	int i;

@@ -1443,6 +1443,7 @@
 	memset(&extract_timer_state, 0, sizeof(struct timer_rand_state));
 	extract_timer_state.dont_count_entropy = 1;
 }
+module_init(rand_initialize);
 
 void rand_initialize_irq(int irq)
 {

drivers/char/tty_io.c +2 -1

@@ -2364,7 +2364,7 @@
  * Ok, now we can initialize the rest of the tty devices and can count
  * on memory allocations, interrupts etc..
  */
-void __init tty_init(void)
+static void __init tty_init(void)
 {
 	strcpy(tty_cdev.kobj.name, "dev.tty");
 	cdev_init(&tty_cdev, &tty_fops);

@@ -2454,3 +2454,4 @@
 	a2232board_init();
 #endif
 }
+module_init(tty_init);

drivers/char/ftape/lowlevel/ftape-init.c +15 ~~-23~~

@@ -55,14 +55,24 @@
 char ft_dat[] __initdata = "$Date: 1997/11/06 00:38:08 $";
 
 
+#ifndef CONFIG_FT_NO_TRACE_AT_ALL
+static int ft_tracing = -1;
+#endif
+
+
 /*  Called by modules package when installing the driver
  *  or by kernel during the initialization phase
  */
-int __init ftape_init(void)
+static int __init ftape_init(void)
 {
 	TRACE_FUN(ft_t_flow);
 
 #ifdef MODULE
+#ifndef CONFIG_FT_NO_TRACE_AT_ALL
+	if (ft_tracing != -1) {
+		ftape_tracing = ft_tracing;
+	}
+#endif
 	printk(KERN_INFO FTAPE_VERSION "\n");
         if (TRACE_LEVEL >= ft_t_info) {
 		printk(

@@ -112,13 +122,6 @@
 #endif
 	TRACE_EXIT 0;
 }
-
-#ifdef MODULE
-
-#ifndef CONFIG_FT_NO_TRACE_AT_ALL
-static int ft_tracing = -1;
-#endif
-
 #define FT_MOD_PARM(var,type,desc) \
 	MODULE_PARM(var,type); MODULE_PARM_DESC(var,desc)

@@ -141,21 +144,7 @@
 	"QIC-117 driver for QIC-40/80/3010/3020 floppy tape drives.");
 MODULE_LICENSE("GPL");
 
-/*  Called by modules package when installing the driver
- */
-int init_module(void)
-{
-#ifndef CONFIG_FT_NO_TRACE_AT_ALL
-	if (ft_tracing != -1) {
-		ftape_tracing = ft_tracing;
-	}
-#endif
-	return ftape_init();
-}
-
-/*  Called by modules package when removing the driver
- */
-void cleanup_module(void)
+static void __exit ftape_exit(void)
 {
 	TRACE_FUN(ft_t_flow);

@@ -167,3 +156,6 @@
 	TRACE_EXIT;
 }
 #endif /* MODULE */
+
+module_init(ftape_init);
+module_exit(ftape_exit);

include/linux/ftape.h +0 -2

@@ -199,8 +199,6 @@
 #define ABS(a)          ((a) < 0 ? -(a) : (a))
 #define NR_ITEMS(x)     (int)(sizeof(x)/ sizeof(*x))
 
-extern int ftape_init(void);
-
 #endif  /* __KERNEL__ */
 
 #endif

include/linux/miscdevice.h +0 -2

@@ -34,8 +34,6 @@
 
 #define TUN_MINOR	     200
 
-extern int misc_init(void);
-
 struct miscdevice 
 {
 	int minor;

include/linux/random.h +0 -1

@@ -42,7 +42,6 @@
 
 #ifdef __KERNEL__
 
-extern void rand_initialize(void);
 extern void rand_initialize_irq(int irq);
 
 extern void batch_entropy_store(u32 a, u32 b, int num);

include/linux/tty.h +0 -1

@@ -351,7 +351,6 @@
 
 extern int lp_init(void);
 extern int pty_init(void);
-extern void tty_init(void);
 extern int mxser_init(void);
 extern int moxa_init(void);
 extern int ip2_init(void);