Messages in this thread | | | Date | Mon, 27 Aug 2001 08:52:45 -0600 | From | Richard Gooch <> | Subject | Re: [PATCH] Added devfs support for i386 msr/cpuid driver |
| |
Arjan van de Ven writes: > > > > int __init msr_init(void) > > { > > +#ifdef CONFIG_DEVFS_FS > > + devfs_handle = devfs_register(NULL, "cpu/msr", DEVFS_FL_DEFAULT, 0, 0, > > + S_IFREG | S_IRUGO | S_IWUSR, > > + &msr_fops, NULL); > > +#else > > if (register_chrdev(MSR_MAJOR, "cpu/msr", &msr_fops)) { > > printk(KERN_ERR "msr: unable to get major %d for msr\n", > > MSR_MAJOR); > > return -EBUSY; > > } > > +#endif > > this must be wrong as you don't check for devfs_register failures...
The reason it's wrong is because he put #ifdef's in there. The functions should just be called unconditionally. The #ifdef's are in the header.
> Also why devfs can't just use register_chrdev and not touch ALL > drivers is beyond me, but it has been like that for a while now...
Huh?!? I thought that should be obvious. Think about it, register_chrdev() registers a *major*, whereas devfs_register() registers an individual device node. The former has no way of representing which devices are detected, the latter sets up a 1:1 relationship between devices and device nodes (which is what people actually want).
Regards,
Richard.... Permanent: rgooch@atnf.csiro.au Current: rgooch@ras.ucalgary.ca - 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/
| |