CONFIG_ARM_ERRATA_775420 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

ARM errata: A data cache maintenance operation which aborts, might lead to deadlock

configname: CONFIG_ARM_ERRATA_775420

Linux Kernel Configuration
└─>System Type
└─>ARM errata: A data cache maintenance operation which aborts, might lead to deadlock
In linux kernel since version 3.0.2 (release Date: 2011-08-15)  
This option enables the workaround for the 775420 Cortex-A9 (r2p2,
r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance
operation aborts with MMU exception, it might cause the processor
to deadlock. This workaround puts DSB before executing ISB if
an abort may occur on cache maintenance.