Messages in this thread Patch in this message | | | Date | Thu, 6 Sep 2007 12:04:31 +0200 | Subject | Re: [PATCH] drivers/char/misc.c: deprecated call register_chrdev, and 256 minor limit eliminated | From | (Renzo Davoli) |
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On Thu, Sep 06, 2007 at 11:38:44AM +0200, Renzo Davoli wrote: Dear Kernel Developers,
I have seen that drivers/char/misc.c already used the deprecated register_chrdev call and this limited the number of minors to 256.
I recetly asked for a misc minor number attribution for View-OS/kmview and Torben Mathiasen told me about this issue.
I propose this patch that eliminate both problems. With this patch misc allocates the entire major 10 and avoids the deprecated call.
These are just my 2 (euro) cents, I hope it can be useful.
renzo
Signed-off-by: Renzo Davoli <renzo@cs.unibo.it>
-- ============================================================================ Renzo Davoli | Dept. of Computer Science (NIC rd235, HAM IZ4DJE) | University of Bologna Tel. +39 051 2094501 | Mura Anteo Zamboni, 7 Fax. +39 051 2094510 | I-40127 Bologna ITALY Key fingerprint = A019 17E2 5562 06F6 77BB 2E93 1A01 F646 30EA B487 ============================================================================
--- drivers/char/misc.orig.c 2007-08-05 16:56:59.000000000 +0200 +++ drivers/char/misc.c 2007-09-06 11:07:51.000000000 +0200 @@ -56,6 +56,8 @@ static LIST_HEAD(misc_list); static DEFINE_MUTEX(misc_mtx); +static struct cdev misc_cdev; + /* * Assigned numbers, used for dynamic minors */ @@ -273,6 +275,31 @@ EXPORT_SYMBOL(misc_register); EXPORT_SYMBOL(misc_deregister); +static int misc_register_chrdev(void) +{ + dev_t from=MKDEV(MISC_MAJOR,0); + int rv; + int err = -ENOMEM; + char *s; + + if ((rv=register_chrdev_region(from,MINORMASK,"misc")) != 0) + return rv; + + cdev_init(&misc_cdev, &misc_fops); + misc_cdev.owner=misc_fops.owner; + kobject_set_name(&misc_cdev.kobj, "%s", "misc"); + for (s = strchr(kobject_name(&misc_cdev.kobj),'/'); s; s = strchr(s, '/')) + *s = '!'; + err = cdev_add(&misc_cdev, from, MINORMASK); + if (err) + goto out; + return 0; +out: + kobject_put(&misc_cdev.kobj); + unregister_chrdev_region(from,MINORMASK); + return err; +} + static int __init misc_init(void) { #ifdef CONFIG_PROC_FS @@ -286,7 +313,7 @@ if (IS_ERR(misc_class)) return PTR_ERR(misc_class); - if (register_chrdev(MISC_MAJOR,"misc",&misc_fops)) { + if (misc_register_chrdev()) { printk("unable to get major %d for misc devices\n", MISC_MAJOR); class_destroy(misc_class);
-- ============================================================================ Renzo Davoli | Dept. of Computer Science (NIC rd235, HAM IZ4DJE) | University of Bologna Tel. +39 051 2094501 | Mura Anteo Zamboni, 7 Fax. +39 051 2094510 | I-40127 Bologna ITALY Key fingerprint = A019 17E2 5562 06F6 77BB 2E93 1A01 F646 30EA B487 ============================================================================ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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