arm/183740: mutex on some arm hardware requires dcache enabled

[John Wehle]

The following reply was made to PR arm/183740; it has been noted by GNATS.

From: John Wehle <john at feith.com>
To: ganbold at gmail.com
Cc: freebsd-gnats-submit at freebsd.org
Subject: Re: arm/183740: mutex on some arm hardware requires dcache enabled
Date: Mon, 11 Nov 2013 01:31:38 -0500 (EST)

 > What kind of Amlogic board you are working on?
 
 I'm currently using a Visson ATV-102 "Android TV Box" which has an
 Amlogic aml8726-m3 SoC.  I have it to the point of attempting to
 mount the root filesystem so it's probably time for me to write a
 driver for the Amlogic MMC hardware.
 
 I also have a Ainol Elf 2 tablet which has an Amlogic aml8726-mx SoC
 which I plan to work on next.
 
 Both chips are dual core Arm Cortex A9 processors.
 
 > As for the patch can you try to put it in initarm_late_init() of
 > your board machdep code and try?
 
 Yep ... enabling the dcache in initarm_late_init takes care of the
 mutex ldrex / strex problem.
 
 -- John