Merge remote-tracking branches 'asoc/topic/ts3a227e', 'asoc/topic/ts3a277e' and ...

[firefly-linux-kernel-4.4.55.git] / arch / x86 / mm / pat.c

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index edf299c8ff6c774dea8116092a41b15102d9cf1c..7ac68698406c3b35e5ce0b0e98c73c5441e869a3 100644 (file)
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -234,8 +234,13 @@ void pat_init(void)
              PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC);
 
        /* Boot CPU check */
-       if (!boot_pat_state)
+       if (!boot_pat_state) {
                rdmsrl(MSR_IA32_CR_PAT, boot_pat_state);
+               if (!boot_pat_state) {
+                       pat_disable("PAT read returns always zero, disabled.");
+                       return;
+               }
+       }
 
        wrmsrl(MSR_IA32_CR_PAT, pat);