[PATCH v2] powerpc: Add workaround for MPICs with broken register reads
miltonm at bga.com
Sat Sep 8 00:11:52 EST 2007
On Sep 7, 2007, at 4:21 AM, Olof Johansson wrote:
> Some versions of PWRficient 1682M have an interrupt controller in which
> the first register in each pair for interrupt sources doesn't always
> read with the right polarity/sense values.
> To work around this, keep a software copy of the register instead.
> it's not modified from the mpic itself, it's a feasible solution.
> keep it under a config option to avoid wasting memory on other
> Signed-off-by: Olof Johansson <olof at lixom.net>
> diff --git a/arch/powerpc/platforms/Kconfig
> index 041df77..f2e7049 100644
> --- a/arch/powerpc/platforms/Kconfig
> +++ b/arch/powerpc/platforms/Kconfig
> @@ -137,6 +137,18 @@ config MPIC_U3_HT_IRQS
> depends on PPC_MAPLE
> default y
> +config MPIC_BROKEN_REGREAD
> + bool "MPIC workaround for broken register reads"
> + depends on MPIC
> + help
> + Say Y here to enable a MPIC driver workaround for some chips that
> + have a bug that causes some interrupt source information to not
> + read back properly. It is safe to use on other chips as well, but
> + enabling it uses about 8KB of memory to keep copies of the register
> + contents in software.
> + Say N if you are unsure.
I'm sorry, I didn't mean to imply it should be asked / selectable, just
that the help should be provided. I won't object to leaving it except
that it asks the average user unnecessary questions. In other words,
drop the question after bool.
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