Re: [PATCH 0/2] ARM: zynq: address silent L2 cache corruption
From: Michal Simek
Date: Tue Feb 09 2016 - 04:19:34 EST
On 3.2.2016 03:30, Josh Cartwright wrote:
> The Zynq has a bug where the L2 cache will return invalid data in some
> circumstances unless the L2C_RAM register is set to 0x20202 before the first
> enabling of the L2 cache.
>
> The Xilinx-recommended solution to this problem is to ensure that early one of
> the earlier bootstages correctly initialize L2C_RAM, however, this issue wasn't
> discovered and fixed until after their EDK/SDK 14.4 release. For systems built
> prior to that, and which lack field-upgradable bootloaders, this issue still
> exists and silent data corruption can be seen in the wild.
>
> Fix these systems by ensuring L2C_RAM is properly initialized at the
> earliest convenient moment prior to the L2 being brought up, which is
> when the SLCR is first mapped.
>
> Unfortunately, there isn't much public documentation on exactly what the
> L2C_RAM register is for, or how it is used, only that software is responsible
> for initializing it to the proper value prior to bringing up L2.
>
> You can find more information about this bug in AR#54190[1].
>
> 1: http://www.xilinx.com/support/answers/54190.html
>
> Josh Cartwright (2):
> ARM: zynq: initialize slcr mapping earlier
> ARM: zynq: address L2 cache data corruption
>
> arch/arm/mach-zynq/common.c | 3 +--
> arch/arm/mach-zynq/slcr.c | 4 ++++
> 2 files changed, 5 insertions(+), 2 deletions(-)
>
Applied both.
Thanks,
Michal