[igt-dev] [PATCH i-g-t 07/10] lib/psr: Drop support to old kernels without new PSR debugfs interface

[Dhinakaran Pandiyan]

On Fri, 2019-01-11 at 17:46 -0800, José Roberto de Souza wrote:
> The nexts patches will add PSR2 tests and for that we need the new
> PSR debugfs interface that was released in kernel 4.20 so it will not
> break for any updated system and we can drop support to the old
> debugsfs and the support to kernels without even a debugfs interface.

Can't we have psr_set(mode == PSR_MODE_2) skip if the kernel does not
support the new interface?


> 
> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>  lib/igt_psr.c | 35 +++++++----------------------------
>  1 file changed, 7 insertions(+), 28 deletions(-)
> 
> diff --git a/lib/igt_psr.c b/lib/igt_psr.c
> index c6638c2c..5cc0fbc2 100644
> --- a/lib/igt_psr.c
> +++ b/lib/igt_psr.c
> @@ -73,27 +73,7 @@ static int has_psr_debugfs(int debugfs_fd)
>  	 * -ENODEV is returned when PSR is unavailable.
>  	 */
>  	ret = psr_write(debugfs_fd, "0xf");
> -	if (ret == -EINVAL)
> -		return 0;
> -	else if (ret < 0)
> -		return ret;
> -
> -	/* legacy debugfs api, we enabled irqs by writing, disable
> them. */
> -	psr_write(debugfs_fd, "0");
> -	return -EINVAL;
> -}
> -
> -static bool psr_modparam_set(int val)
> -{
> -	static int oldval = -1;
> -
> -	igt_set_module_param_int("enable_psr", val);
> -
> -	if (val == oldval)
> -		return false;
> -
> -	oldval = val;
> -	return true;
> +	return ret == -EINVAL ? 0 : ret;
>  }
>  
>  static int psr_restore_debugfs_fd = -1;
> @@ -109,16 +89,15 @@ static bool psr_set(int debugfs_fd, bool enable)
>  
>  	ret = has_psr_debugfs(debugfs_fd);
>  	if (ret == -ENODEV) {
> -		igt_skip_on_f(enable, "PSR not available\n");
> +		igt_skip("PSR not available\n");
> +		return false;
> +	} else if (ret) {
> +		igt_skip("PSR debugfs interface not available\n");
>  		return false;
>  	}
>  
> -	if (ret == -EINVAL) {
> -		ret = psr_modparam_set(enable);
> -	} else {
> -		ret = psr_write(debugfs_fd, enable ? "0x3" : "0x1");
> -		igt_assert(ret > 0);
> -	}
> +	ret = psr_write(debugfs_fd, enable ? "0x3" : "0x1");
> +	igt_assert(ret > 0);
>  
>  	/* Restore original value on exit */
>  	if (psr_restore_debugfs_fd == -1) {