Hi Matteo,
Sorry for the late response. Some personal/work issues
prevented me in reacting faster.
> +static int ar7_wdt_open(struct inode *inode, struct file *file)
> +{
> + /* only allow one at a time */
> + if (down_trylock(&open_semaphore))
> + return -EBUSY;
> + ar7_wdt_enable_wdt();
> + expect_close = 0;
> +
> + return 0;
> +}
The /dev/watchdog device is a VFS (Virtual File System). We thus
use a: return nonseekable_open(inode, file);
> +static ssize_t ar7_wdt_write(struct file *file, const char *data,
> + size_t len, loff_t *ppos)
> +{
> + if (*ppos != file->f_pos)
> + return -ESPIPE;
> +
Since we use the nonseekable_open we don't need the
if (*ppos != file->f_pos) return -ESPIPE;
> +static int __init ar7_wdt_init(void)
> +{
...
> + rc = misc_register(&ar7_wdt_miscdev);
> + if (rc) {
> + printk(KERN_ERR DRVNAME ": unable to register misc device\n");
> + goto out_alloc;
> + }
> +
> + rc = register_reboot_notifier(&ar7_wdt_notifier);
> + if (rc) {
> + printk(KERN_ERR DRVNAME
> + ": unable to register reboot notifier\n");
> + goto out_register;
> + }
> + goto out;
> +
> +out_register:
> + misc_deregister(&ar7_wdt_miscdev);
> +out_alloc:
> + release_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt));
> +out:
> + return rc;
> +}
It's better to first register the reboot-notifier instead of
registering the misc-device. The misc-device gives userspace
allready access to the device and that's something that you
want to do as the last action to prevent problems.
For the rest: all OK.
If you want I'll add it to the linux-2.6-watchdog-mm tree with
the above mentioned changes.
Greetings,
Wim.
