Misc, phantom, fix poll
Jiri Slaby [Tue, 29 Apr 2008 07:59:14 +0000 (00:59 -0700)]
Return ERR even if there are pending data, but hw is not running.  Do not
decrement count in poll, do it in ioctl, where data are actually read.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/misc/phantom.c

index 5447a60..71d1c84 100644 (file)
@@ -169,6 +169,7 @@ static long phantom_ioctl(struct file *file, unsigned int cmd,
                for (i = 0; i < m; i++)
                        if (rs.mask & BIT(i))
                                rs.values[i] = ioread32(dev->iaddr + i);
+               atomic_set(&dev->counter, 0);
                spin_unlock_irqrestore(&dev->regs_lock, flags);
 
                if (copy_to_user(argp, &rs, sizeof(rs)))
@@ -254,11 +255,12 @@ static unsigned int phantom_poll(struct file *file, poll_table *wait)
 
        pr_debug("phantom_poll: %d\n", atomic_read(&dev->counter));
        poll_wait(file, &dev->wait, wait);
-       if (atomic_read(&dev->counter)) {
+
+       if (!(dev->status & PHB_RUNNING))
+               mask = POLLERR;
+       else if (atomic_read(&dev->counter))
                mask = POLLIN | POLLRDNORM;
-               atomic_dec(&dev->counter);
-       } else if ((dev->status & PHB_RUNNING) == 0)
-               mask = POLLIN | POLLRDNORM | POLLERR;
+
        pr_debug("phantom_poll end: %x/%d\n", mask, atomic_read(&dev->counter));
 
        return mask;