Re: [PATCH i-g-t v1.1] lib/igt_gt: Fallback on filenames in igt_open_forcewake_handle()

[Matt Roper <matthew.d.roper@intel.com>]

On Wed, Sep 18, 2024 at 12:16:26PM -0700, Lucas De Marchi wrote:
> If fd is -1, we don't know what file should be used for forcewake.
> We could open the debugfs dir and figure out from there, but it's also
> cheap to just handle a fallback approach. Ideally fd == -1 wouldn't be
> passed and eventually this could be removed.
> 
> v2: Fix copy-and-paste error s/XE/I915/
> 
> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>

> ---
>  lib/igt_gt.c | 24 +++++++++++++++++++-----
>  1 file changed, 19 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/igt_gt.c b/lib/igt_gt.c
> index c84368fbd..4b096768f 100644
> --- a/lib/igt_gt.c
> +++ b/lib/igt_gt.c
> @@ -502,17 +502,31 @@ void igt_stop_hang_helper(void)
>   */
>  int igt_open_forcewake_handle(int fd)
>  {
> -	const char *fn;
> +	enum {
> +		I915,
> +		XE,
> +	};
> +	const char *fn[] = {
> +		[I915] = "i915_forcewake_user",
> +		[XE] = "forcewake_all",
> +	};
>  
>  	if (getenv("IGT_NO_FORCEWAKE"))
>  		return -1;
>  
>  	if (is_xe_device(fd))
> -		fn = "forcewake_all";
> -	else
> -		fn = "i915_forcewake_user";
> +		return igt_debugfs_open(fd, fn[XE], O_RDONLY);
> +	if (is_i915_device(fd))
> +		return igt_debugfs_open(fd, fn[I915], O_RDONLY);
> +
> +	for (unsigned int i = 0; i < ARRAY_SIZE(fn); i++) {
> +		int ret = igt_debugfs_open(fd, fn[i], O_RDONLY);
> +
> +		if (ret >= 0)
> +			return ret;
> +	}
>  
> -	return igt_debugfs_open(fd, fn, O_RDONLY);
> +	return -ENOENT;
>  }
>  
>  #if defined(__x86_64__) || defined(__i386__)
> -- 
> 2.46.1
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation