[+cc Huacai and Kai-Heng as they are working in this area] Hi, Thank you for sending the patch over. I assume this is simply a resend (rather than a v2), as I see no code changes from the previous version you sent some time ago. > Add writing attribute for boot_vga sys node, > so we can config default video display > output dynamically when there are two video > cards on a machine. That's OK, but why are you adding this? What problem does it solve and what is the intended user here? Might be worth adding a little bit more details about why this new sysfs attribute is needed. I also need to ask, as I am not sure myself, whether this is OK to do after booting during runtime? What do you think Bjorn, Huacai and Kai-Heng? Also, please correctly capitalise the subject - have a look at previous commit messages to see how it should look like. > +static ssize_t boot_vga_store(struct device *dev, struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + unsigned long val; > + struct pci_dev *pdev = to_pci_dev(dev); > + struct pci_dev *vga_dev = vga_default_device(); > + > + if (kstrtoul(buf, 0, &val) < 0) > + return -EINVAL; > + > + if (val != 1) > + return -EINVAL; Since this is a completely new API have a look at kstrtobool() over kstrtoul() as the former was created to handle user input more consistently. > + if (!capable(CAP_SYS_ADMIN)) > + return -EPERM; > + Check for CAP_SYS_ADMIN is a good idea, but it has to take place before you attempt to accept and parse a input from the user. Krzysztof