Re: [PATCH 4/6] persistent_ram: Move to fs/pstore/ram_core.c

On Wed, May 16, 2012 at 5:43 AM, Anton Vorontsov anton.vorontsov@linaro.org wrote:

This is a first step for adding ECC support for pstore RAM backend: we will use the persistent_ram routines, kindly provided by Google.

Basically, persistent_ram is a set of helper routines to deal with the [optionally] ECC-protected persistent ram regions.

...

+static int persistent_ram_init_ecc(struct persistent_ram_zone *prz,

• size_t buffer_size)

+{

• int numerr;
• struct persistent_ram_buffer *buffer = prz->buffer;
• int ecc_blocks;
• if (!prz->ecc)
• return 0;
• prz->ecc_block_size = 128;
• prz->ecc_size = 16;

I realize you are just moving code here, but 16 ecc bytes for per 128 bytes of data can only correct 8 bad bytes, which is not always sufficient. At some point this will need to be made configurable again.