Re: [ RFC, PATCH - 1/2, v2 ] x86-microcode: refactor microcode output messages

[Dmitry Adamushko <dmitry.adamushko@gmail.com>]

2009/11/12 Dmitry Adamushko <dmitry.adamushko@gmail.com>:
> 2009/11/12 Ingo Molnar <mingo@elte.hu>:
>>
>> -tip testing found the following bug - there's a _long_ boot delay of
>> 58.6 seconds if the CPU family is not supported:
>>
>> [    1.421761] calling  microcode_init+0x0/0x137 @ 1
>> [    1.426532] platform microcode: firmware: requesting amd-ucode/microcode_amd.bin
>> [   61.433126] microcode: failed to load file amd-ucode/microcode_amd.bin
>> [   61.439682] microcode: CPU0: AMD CPU family 0xf not supported
>> [   61.445441] microcode: CPU1: AMD CPU family 0xf not supported
>> [   61.451273] Microcode Update Driver: v2.00 <tigran@aivazian.fsnet.co.uk>, Peter Oruba
>> [   61.459116] initcall microcode_init+0x0/0x137 returned 0 after 58625622 usecs
>>
>> Where does this delay come from?
>
> My guess is that it's comming from
>
> static int loading_timeout = 60;        /* In seconds */
>
> drivers/base/firmware_class.c
>
> given that you seem to have MICROCODE build in kernel, so this patch
> http://git.kernel.org/?p=linux/kernel/git/x86/linux-2.6-tip.git;a=commit;h=d1c84f79a6ba992dc01e312c44a21496303874d6
>
> will result in sending a request for a firmware image to user-space
> (unless that firmware image is also built-in into the kernel) and
> user-space has not started yet.

btw., it doesn't make sense for request_firmware() to even try this if
the system_state != SYSTEM_RUNNING and current == 'init' (it'd perhaps
make some sense if it's been done in a context of another task -- like
in case of a parallel boot).

And perhaps it just makes sense for microcode to use request_firmware_nowait().


-- Dmitry