Re: [PATCH v2 1/1] mfd: intel-lpss: Try to enable Memory-Write-Invalidate

From: Mika Westerberg
Date: Thu Nov 17 2016 - 04:09:47 EST


On Tue, Nov 15, 2016 at 12:37:04PM +0200, Andy Shevchenko wrote:
> Enable MWI mechanism if PCI bus master supports it.
>
> It might be potential benefit in some cases. Documentation [1] says that
> standard Memory Write might supply more current data than in the CPU modified
> cache line and "trashing a line in the cache may trash some data that is more
> current that in the memory line". This allows to avoid potential retries and
> other performance degradation issues on the bus.
>
> [1] PCI System Architecture, 4th edition, ISBN: 0-201-30974-2, pp.117-119.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>