On Tue, Dec 26, 2017 at 09:44:31AM +0800, Jia Zhang wrote:
> Instead of blacklisting all Broadwell processorsi for running a late
^^^^^^^^^^^
Please run all text in this patch through a spellchecker.
> loading, only BDW-EP (signature 406f1) with the microcode version
Please write out what that signature actually is - it might be confusing
to people not dealing with family/model/stepping on a daily basis.
> less than 0x0b000021 needs to be blacklisted.
>
> This is documented in the the public documentation #334165 (See the
> item BDF90 for details).
>
> Signed-off-by: Jia Zhang <[email protected]>
> ---
> arch/x86/kernel/cpu/microcode/intel.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/microcode/intel.c
> b/arch/x86/kernel/cpu/microcode/intel.c
> index 8ccdca6..d2c1638 100644
> --- a/arch/x86/kernel/cpu/microcode/intel.c
> +++ b/arch/x86/kernel/cpu/microcode/intel.c
> @@ -910,8 +910,15 @@ static bool is_blacklisted(unsigned int cpu)
> {
> struct cpuinfo_x86 *c = &cpu_data(cpu);
>
> - if (c->x86 == 6 && c->x86_model == INTEL_FAM6_BROADWELL_X) {
> - pr_err_once("late loading on model 79 is disabled.\n");
> + /*
> + * The Broadwell-EP processor with the microcode version less
> + * then 0x0b000021 may reault in system hang when running a late
^^^^^^
typo.
> + * loading. This behavior is documented in item BDF90, #334165
> + * (Intel Xeon Processor E7-8800/4800 v4 Product Family).
> + */
> + if (c->x86 == 6 && c->x86_model == INTEL_FAM6_BROADWELL_X &&
> + c->x86_mask == 0x01 && c->microcode < 0x0b000021U) {
^
The appended 'U' is for? I mean, I'd expect the implicit promotion rules
to kick in here as always. :-)
> + pr_err_once("late loading on model 79 (sig 64f1) is
> disabled.\n");
See, you can get the sig wrong yourself too. Or were you trying to write
family/model/stepping in some short form?
Also, this error message needs to explain exactly why late loading is
disabled - because microcode revision is < 0x0b000021.
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
