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SubjectRe: [PATCH 4/5] uio: Support 2^MINOR_BITS minors
On Fri, Sep 17, 2010 at 10:36:50PM +0200, Thomas Gleixner wrote:
> On Tue, 14 Sep 2010, Eric W. Biederman wrote:
>
> >
> > register_chrdev limits uio devices to 256 minor numbers which causes
> > problems on one system I have with 384+ uio devices. So instead set
> > UIO_MAX_DEVICES to the maximum number of minors and use
> > alloc_chrdev_region to reserve the uio minors.
> >
> > The final result is that the code works the same but the uio driver now
> > supports any minor the idr allocator comes up with.
> >
> > Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
>
> One minor nit:
>
> > + result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
> > + if (result)
> > + goto out;
>
> return result;

Well, ok... Greg, can you fix this when you take the patch into your tree?

>
> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Hans J. Koch <hjk@linutronix.de>

>
> > +
> > + result = -ENOMEM;
> > + cdev = cdev_alloc();
> > + if (!cdev)
> > + goto out_unregister;
> > +
> > + cdev->owner = THIS_MODULE;
> > + cdev->ops = &uio_fops;
> > + kobject_set_name(&cdev->kobj, "%s", name);
> > +
> > + result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
> > + if (result)
> > + goto out_put;
> > +
> > + uio_major = MAJOR(uio_dev);
> > + uio_cdev = cdev;
> > + result = 0;
> > +out:
> > + return result;
> > +out_put:
> > + kobject_put(&cdev->kobj);
> > +out_unregister:
> > + unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
> > + goto out;
> > }
> >
> > static void uio_major_cleanup(void)
> > {
> > - unregister_chrdev(uio_major, "uio");
> > + unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
> > + cdev_del(uio_cdev);
> > }
> >
> > static int init_uio_class(void)
> > --
> > 1.7.2.2
> >
> > --
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> >


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