[igt-dev] [PATCH i-g-t] lib/igt_psr: Added ENOENT error check to psr_set for older kernels

[Dhinakaran Pandiyan]

On Friday, September 28, 2018 5:01:31 PM PDT Casey Bowman wrote:
> Only EINVAL was being used to account for older kernels,
> but on legacy kernels that don't use i915_edp_psr_debug,
> the ENOENT error will be thrown. This changes the logic
> to also account for ENOENT errors.
> 
> Signed-off-by: Casey Bowman <casey.g.bowman at intel.com>
> ---
>  lib/igt_psr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/igt_psr.c b/lib/igt_psr.c
> index 0ddfb64f..8cb41a55 100644
> --- a/lib/igt_psr.c
> +++ b/lib/igt_psr.c
> @@ -103,7 +103,7 @@ static bool psr_set(int debugfs_fd, bool enable)
>  		return false;
>  	}
> 
> -	if (ret == -EINVAL) {
> +	if (ret == -EINVAL || ret == -ENOENT) {

Please move this logic to has_psr_debugfs() and expand the existing 
documentation about return values from the kernel.

-DK


>  		ret = psr_modparam_set(enable);
>  	} else {
>  		ret = psr_write(debugfs_fd, enable ? "0x3" : "0x1");