sysfs_remove_group(&pdev->dev.kobj, &smsc47b397_group);
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
release_region(res->start, SMSC_EXTENT);
sysfs_remove_group(&pdev->dev.kobj, &smsc47b397_group);
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
release_region(res->start, SMSC_EXTENT);