[PATCH v4 2/3] mmc: core: add random fault injection

[Akinobu Mita]

2011/7/27 Per Forlin <per.forlin at linaro.org>:
> This adds support to inject data errors after a completed host transfer.
> The mmc core will return error even though the host transfer is successful.
> This simple fault injection proved to be very useful to test the
> non-blocking error handling in the mmc_blk_issue_rw_rq().
> Random faults can also test how the host driver handles pre_req()
> and post_req() in case of errors.

Looks good but I have one question.

> @@ -304,6 +307,10 @@ struct mmc_host {
>
>        struct mmc_async_req    *areq;          /* active async req */
>
> +#ifdef CONFIG_FAIL_MMC_REQUEST
> +       u8                      make_it_fail;
> +       struct fault_attr       fail_mmc_request;
> +#endif
>        unsigned long           private[0] ____cacheline_aligned;
>  };

I think make_it_fail is not needed anymore because if fail_attr is
defined per-host then you can enable it by setting probability=0
or times=0 per-host.