On Thu, 16 Apr 2015 20:27:00 +0300, subscivan wrote: > On 16.04.15 18:44, Jean Delvare wrote: > > Le Thursday 16 April 2015 à 15:56 +0300, Ivan.khoronzhuk a écrit : > >> We cannot be sure that firmware_kobj created at time of dmi_init(). > >> The sources don't oblige you to call it at core level, > >> for instance like it was done for arm64. For x86, dmi_init() can be called > >> before firmware_kobj is created. > > Looking at the code, it seems that firmware_kobj is created very, very > > early in the boot process. In do_basic_setup(), you can see that > > driver_init() (which in turn calls firmware_init(), creating > > firmware_kobj) is called before do_initcalls(). So firmware_kobj must be > > defined before dmi_scan_machine() or dmi_init() is called. > > No. Not must, rather should. See below. > > > Oh, and this wasn't even my point ;-) I'm fine with you checking if > > firmware_kobj is defined. My question was about the dmi_available check > > above. But that question was silly anyway, sorry. I confused > > dmi_available with dmi_initialized. Checking for dmi_available is > > perfectly reasonable, please scratch my objection. > > > >> And if I call it from dmi_init() I suppose > >> I would face an error. As I can't call it in dmi_init I can't be sure that > >> DMI is available at all. So, no, we have to check dmi_available here and > >> call it at subsys layer, where it's supposed to be. > > I can't parse that, I suspect you wrote dmi_init where you actually > > meant dmi_scan_machine? Given how early firmware_kobj is created, I > > think the code currently in dmi_init could in fact go at the end of > > dmi_scan_machine. > > Actually, dmi_scan_machine can be called even earlier. > As I've sad, for x86, it's called before firmware_kobj is created. > > kernel_start() > setup_arch() > dmi_scan_machine() > > And for firmware_init(), as you noticed already: > > start_kernel() > rest_init() > kernel_init() > kernel_init_freeable() > do_basic_setup() > driver_init() > firmware_init() > > Pay attentions that setup_arch() is called much earlier than rest_init(). > So dmi_init couldn't in fact go at the end of dmi_scan_machine. Yeah, you're right, sorry. Somehow I thought that setup_arch was an arch_initcall, but it is not, so I got the order all wrong. -- Jean Delvare SUSE L3 Support -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
