[igt-dev] [PATCH i-g-t] tests/psr: Skip if PSR cannot be enabled for the current mode.

[Chris Wilson]

Quoting Dhinakaran Pandiyan (2018-08-01 07:43:23)
> PSR tests on ICL fail waiting for PSR to become active, whereas the
> driver does not enable it on the HW due to unmet timing requirements
> [  482.485873] [drm:intel_dp_compute_config [i915]] PSR condition failed: PSR setup time (330 us) too long
> We should probably bring back the kernel patch that programmed an alternate
> mode, but skip tests for now.
> 
> Cc: José Roberto de Souza <jose.souza at intel.com>
> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> ---
>  tests/kms_psr.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/kms_psr.c b/tests/kms_psr.c
> index 218b3960..89118ad4 100644
> --- a/tests/kms_psr.c
> +++ b/tests/kms_psr.c
> @@ -193,11 +193,19 @@ static bool sink_support(data_t *data)
>         char buf[512];
>  
>         igt_debugfs_read(data->drm_fd, "i915_edp_psr_status", buf);
> -
>         return data->with_psr_disabled ||
>                 strstr(buf, "Sink_Support: yes\n");
>  }
>  
> +static bool mode_support(data_t *data)
> +{
> +       char buf[512];

For both of these, we don't even need to read debugfs if data->with_psr_disabled.

> +       igt_debugfs_read(data->drm_fd, "i915_edp_psr_status", buf);

If you are reading the debugfs frequently, cache the debugfs dir

data->debugfs = igt_debugfs_dir(data->drm_fd);

Then use igt_sysfs_read(data->debugfs, "i915_edp_psr_status", buf, sizeof(buf));

> +       return data->with_psr_disabled ||
> +               strstr(buf, "Enabled: yes\n");

Is there any delay before PSR is enabled?

We really should adopt yaml (mild background rant).
-Chris