On Fri, Sep 03, 2021 at 03:45:47PM -0500, Ian Pilcher wrote: > +static ssize_t blkdev_mode_store(struct device *const dev, > + struct device_attribute *const attr, > + const char *const buf, const size_t count) > +{ > + struct ledtrig_blkdev_led *const led = led_trigger_get_drvdata(dev); > + const char *const mode_name = blkdev_skip_space(buf); > + const char *const endp = blkdev_find_space(mode_name); > + const ptrdiff_t name_len = endp - mode_name; /* always >= 0 */ > + enum ledtrig_blkdev_mode mode; > + > + if (name_len == 0) { > + pr_info("blkdev LED: empty mode\n"); > + return -EINVAL; > + } > + > + for (mode = LEDTRIG_BLKDEV_MODE_RO; > + mode <= LEDTRIG_BLKDEV_MODE_RW; ++mode) { > + > + if (ledtrig_blkdev_streq(blkdev_modes[mode].name, > + mode_name, name_len)) { > + WRITE_ONCE(led->mode, mode); > + return count; > + } > + } > + > + pr_info("blkdev LED: invalid mode (%.*s)\n", (int)name_len, mode_name); Please do not use pr_* calls in a driver when you have a struct device. Also, you are now allowing any user to spam the kernel log, this shold be a dev_dbg() call at the most, if it is even needed at all. Same for the other pr_info() call in this function, please remove them all. thanks, greg k-h