4.14-stable review patch. If anyone has any objections, please let me know.
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From: Len Brown len.brown@intel.com
commit a4c447533a18ee86e07232d6344ba12b1f9c5077 upstream.
When MWAIT is disabled, intel_idle refuses to probe. But it may mis-lead the user by blaming this on the model number:
intel_idle: does not run on family 6 modesl 79
So defer the check for MWAIT until after the model# white-list check succeeds, and if the MWAIT check fails, tell the user how to fix it:
intel_idle: Please enable MWAIT in BIOS SETUP
Signed-off-by: Len Brown len.brown@intel.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Cc: Eduardo Valentin eduval@amazon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/idle/intel_idle.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -1061,7 +1061,7 @@ static const struct idle_cpu idle_cpu_dn };
#define ICPU(model, cpu) \ - { X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu } + { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&cpu }
static const struct x86_cpu_id intel_idle_ids[] __initconst = { ICPU(INTEL_FAM6_NEHALEM_EP, idle_cpu_nehalem), @@ -1125,6 +1125,11 @@ static int __init intel_idle_probe(void) return -ENODEV; }
+ if (!boot_cpu_has(X86_FEATURE_MWAIT)) { + pr_debug("Please enable MWAIT in BIOS SETUP\n"); + return -ENODEV; + } + if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF) return -ENODEV;