My patch can't cause this. I'd be surprised if my patch has any effect beyond silencing a static checker warning, honestly. I'm not sure this is a new bug. The problem is we hold ->mmap_sem when we call fb_release() which takes the info->lock. We take the info->lock in do_fb_ioctl() before we call fb_set_var() which calls drm_fb_helper_set_par() which takes the mode_config.mutex. In drm_mode_getresources() we take the mode_config.mutex() and call put_user() which takes the ->mmap_sem. So on one CPU we are holding the ->mmap_sem and want the info->lock. On another CPU we are holding the info->lock and want the config.mutex. On the other CPU we hold the config.mutex and want the ->mmap_sem. Deadlock. I'm not sure how to make this work with just two CPUs... Or how to fix it. But I'm going to disclaim all responsibility and hope the fbdev people can take a look. ;) regards, dan carpenter -- 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
