Re: [PATCH] drm/xe/configfs: Fix engine class parsing

[Raag Jadav <raag.jadav@intel.com>]

On Mon, Sep 22, 2025 at 03:12:10PM -0700, Lucas De Marchi wrote:
> If mask is NULL, only the engine class should be accepted, so the
> pattern string should be completely parsed. This should fix passing e.g.
> rcs0 to ctx_restore_post_bb when it's only expecting the engine class.

Should we add to the doc so we don't mix up expectations between different
attributes?

Or do we care about the rest of pattern of mask is NULL? Perhaps it'll
allow us to have common expectations between attributes.

Raag

> Reported-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
> Closes: https://lore.kernel.org/r/20250922155544.67712-1-jonathan.cavitt@intel.com
> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_configfs.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c
> index 8a9b950e7a6d1..beade13efbae7 100644
> --- a/drivers/gpu/drm/xe/xe_configfs.c
> +++ b/drivers/gpu/drm/xe/xe_configfs.c
> @@ -324,8 +324,8 @@ static const struct engine_info *lookup_engine_info(const char *pattern, u64 *ma
>  			continue;
>  
>  		pattern += strlen(engine_info[i].cls);
> -		if (!mask && !*pattern)
> -			return &engine_info[i];
> +		if (!mask)
> +			return *pattern ? NULL : &engine_info[i];
>  
>  		if (!strcmp(pattern, "*")) {
>  			*mask = engine_info[i].mask;
> -- 
> 2.50.1
>