On Tuesday 08 December 2015 13:29:22 John Stultz wrote: > diff --git a/arch/arm/boot/dts/qcom-apq8064-nexus7-flo.dts b/arch/arm/boot/dts/qcom-apq8064-nexus7-flo.dts > index 5183d18..ee5dcb7 100644 > --- a/arch/arm/boot/dts/qcom-apq8064-nexus7-flo.dts > +++ b/arch/arm/boot/dts/qcom-apq8064-nexus7-flo.dts > @@ -282,6 +282,15 @@ > }; > }; > > + reboot_reason: reboot_reason@2a03f65c { > + compatible = "reboot_reason"; This is not a good compatible string. There should generally be a vendor name associated with it (use "linux," if nothing else, and you should have '-' instead of '_'. > + reg = <0x2A03F65C 0x4>; This may easily conflict with the device it is part of. We should have non-overlapping register areas in general. For the example you are looking at, which register block is this? > + > +/* Types of reasons */ > +static enum { > + NONE, > + BOOTLOADER, > + RECOVERY, > + OEM, > + MAX_REASONS > +} __maybe_unused reason_types; The variable seems to always be unused, not just "__maybe_unused". Maybe remove it? > +static int reboot_reason(struct notifier_block *nb, unsigned long action, > + void *data) > +{ > + char *cmd = (char *)data; > + long reason = reasons[NONE]; > + > + if (!reboot_reason_addr) > + return NOTIFY_DONE; > + > + if (cmd != NULL) { > + if (!strncmp(cmd, "bootloader", 10)) > + reason = reasons[BOOTLOADER]; > + else if (!strncmp(cmd, "recovery", 8)) > + reason = reasons[RECOVERY]; > + else if (!strncmp(cmd, "oem-", 4)) { > + unsigned long code; > + > + if (!kstrtoul(cmd+4, 0, &code)) > + reason = reasons[OEM] | (code & 0xff); > + } > + } > + > + if (reason != -1) > + writel(reason, reboot_reason_addr); > + return NOTIFY_DONE; > +} Will this reboot the machine? > + /* Install the notifier */ > + restart_nb.notifier_call = reboot_reason; > + restart_nb.priority = 256; > + if (register_restart_handler(&restart_nb)) { If not, you should use register_reboot_notifier() rather than register_restart_handler(). The former gets called to do something just before rebooting, while the latter attempts to actually reboot the machine. > +static int __init reboot_reason_init(void) > +{ > + return platform_driver_register(&reboot_reason_driver); > +} > +arch_initcall(reboot_reason_init); Why this early? If it can be a normal device_initcall, you can use module_platform_driver(). Arnd -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html