Re: [PATCH] powerpc/fsl-booke: Work around erratum A-006958
From: Aneesh Kumar K.V <hidden>
Date: 2013-07-15 06:03:32
Scott Wood [off-list ref] writes:
quoted hunk ↗ jump to hunk
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index ae0aaea..7f0e2e5 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype@@ -165,6 +165,17 @@ config PPC_E500MC such as e5500/e6500), and must be disabled for running on e500v1 or e500v2. +config FSL_ERRATUM_A_006958 + bool + depends on PPC_E500MC && PPC64 + default y + help + Workaround for erratum A-006958, which says that 64-bit + timebase reads are not atomic. The workaround is to fall back + to the 32-bit method of reading timebase. Note that timebase + is readable by userspace, so any non-vdso userspace accesses + will need to have the workaround applied separately. + config PPC_FPU bool default y if PPC64
I am completely new to this area, so ignore if it is silly. But how do we expect to select this config ? Should that happen via .config ? That seems strange, because without this change some of the configs will surely be broken/buggy right ?. I was expecting it not be a config entry, primarily because I haven't seem something similar on other archs. And if there is an erratum against a cpu release, we should by default apply this when we know we are running on those cpus right ? Which implies this should not be a config option ? -aneesh