[igt-dev] [PATCH i-g-t v2] igt/drv_module_reload: Revamp fault-injection

[Antonio Argenziano]

On 06/06/18 10:42, Chris Wilson wrote:
> The current method of checking for a failed module load is flawed, as we
> only report the error on probing it is not being reported back by
> modprobe. So we have to dig inside the module_parameters while the
> module is still loaded to discover the error.
> 
> v2: Expect i915.inject_load_failure to be zero on success
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Michał Winiarski <michal.winiarski at intel.com>
> Cc: Imre Deak <imre.deak at intel.com>
> Reviewed-by: Michał Winiarski <michal.winiarski at intel.com>
> ---
>   tests/drv_module_reload.c | 45 ++++++++++++++++++++++++++++++++++-----
>   1 file changed, 40 insertions(+), 5 deletions(-)
> 
> diff --git a/tests/drv_module_reload.c b/tests/drv_module_reload.c
> index 092982960..e18aaea5e 100644
> --- a/tests/drv_module_reload.c
> +++ b/tests/drv_module_reload.c
> @@ -234,6 +234,38 @@ reload(const char *opts_i915)
>   	return err;
>   }
>   

>   static void
>   gem_sanitycheck(void)
>   {
> @@ -323,12 +355,15 @@ igt_main
>   		igt_assert_eq(reload("disable_display=1"), 0);
>   
>   	igt_subtest("basic-reload-inject") {
> -		char buf[64];
>   		int i = 0;
> -		do {
> -			snprintf(buf, sizeof(buf),
> -				 "inject_load_failure=%d", ++i);
> -		} while (reload(buf));
> +
> +		igt_i915_driver_unload();
> +
> +		while (inject_fault("i915", "inject_load_failure", ++i) == 0)
> +			;
> +
> +		/* We expect to hit at least one fault! */
> +		igt_assert(i > 1);

I think Michal's patch adds the number of available checkpoints in a 
debugfs, should we trust the driver and assert on: amount of checkpoints 
hit != available checkpoints? Or maybe just spew out a warning.

Thanks,
Antonio

>   	}
>   
>   	igt_fixture {
>