On Tue, Feb 15, 2011 at 03:35:44PM +0800, Eric Miao wrote: > > @@ -720,12 +726,10 @@ static int overlayfb_open(struct fb_info *info, int user) > > if (user == 0) > > return -ENODEV; > > > > - /* allow only one user at a time */ > > - if (atomic_inc_and_test(&ofb->usage)) > > - return -EBUSY; > > + if (ofb->usage++ == 0) > > + /* unblank the base framebuffer */ > > + fb_blank(&ofb->fbi->fb, FB_BLANK_UNBLANK); > > The change above allows multiple user at a time? Then I guess > some other places need to be changed accordingly to avoid the > racing conditions. You can't prevent multiple users. Think threaded applications which share the same set of fds. Any driver which tries to do so by restricting the number of open()s is simply buggy. -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
