Commit a8d68290 authored by Thomas Gleixner's avatar Thomas Gleixner

x86: prevent C-states hang on AMD C1E enabled machines

Impact: System hang when AMD C1E machines switch into C2/C3

AMD C1E enabled systems do not work with normal ACPI C-states 
even if the BIOS is advertising them. Limit the C-states to 
C1 for the ACPI processor idle code.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 27ce4cb4
......@@ -272,6 +272,7 @@ static void c1e_idle(void)
c1e_detected = 1;
mark_tsc_unstable("TSC halt in C1E");
printk(KERN_INFO "System has C1E enabled\n");
set_cpu_cap(&boot_cpu_data, X86_FEATURE_AMDC1E);
}
}
......
......@@ -140,6 +140,8 @@ static inline unsigned int acpi_processor_cstate_check(unsigned int max_cstate)
boot_cpu_data.x86_model <= 0x05 &&
boot_cpu_data.x86_mask < 0x0A)
return 1;
else if (boot_cpu_has(X86_FEATURE_AMDC1E))
return 1;
else
return max_cstate;
}
......
......@@ -81,6 +81,7 @@
#define X86_FEATURE_LFENCE_RDTSC (3*32+18) /* Lfence synchronizes RDTSC */
#define X86_FEATURE_11AP (3*32+19) /* Bad local APIC aka 11AP */
#define X86_FEATURE_NOPL (3*32+20) /* The NOPL (0F 1F) instructions */
#define X86_FEATURE_AMDC1E (3*32+21) /* AMD C1E detected */
/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */
......
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