CONFIG_ARM_ERRATA_821420 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock
configname: CONFIG_ARM_ERRATA_821420
Linux Kernel Configuration
└─>System Type
└─>ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock
In linux kernel since version 4.1 (release Date: 2015-06-21)
This option enables the workaround for the 821420 Cortex-A12
(all revs) erratum. In very rare timing conditions, a sequence
of VMOV to Core registers instructions, for which the second
one is in the shadow of a branch or abort, can lead to a
deadlock when the VMOV instructions are issued out-of-order.
(all revs) erratum. In very rare timing conditions, a sequence
of VMOV to Core registers instructions, for which the second
one is in the shadow of a branch or abort, can lead to a
deadlock when the VMOV instructions are issued out-of-order.