[igt-dev] [PATCH i-g-t v1] tests/kms_writeback: Add helper method to detach pipe from output when test finishes

[Petri Latvala]

On Fri, May 13, 2022 at 04:48:38PM -0700, Jessica Zhang wrote:
> Currently, after a writeback test is run, the writeback connecter doesn't
> release the pipe for other connecters to use. This can cause the device
> to crash if another connector tries to use the same pipe (for other IGT
> tests, for example).
> 
> In addition, a slight change [1] to DRM's implementation of the rmfb ioctl
> means that calling igt_remove_fb() alone will not detach the CRTC --
> instead, an explicit disable will be needed to do that.
> 
> [1]
> https://gitlab.freedesktop.org/drm/msm/-/blob/msm-next/drivers/gpu/drm/drm_framebuffer.c#L997
> 
> Signed-off-by: Jessica Zhang <quic_jesszhan at quicinc.com>

Reviewed-by: Petri Latvala <petri.latvala at intel.com>

> ---
>  tests/kms_writeback.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/tests/kms_writeback.c b/tests/kms_writeback.c
> index 21d62faabf6b..b6c815db413c 100644
> --- a/tests/kms_writeback.c
> +++ b/tests/kms_writeback.c
> @@ -139,6 +139,11 @@ static igt_output_t *kms_writeback_get_output(igt_display_t *display)
>  	return NULL;
>  }
>  
> +static void detach_crtc(igt_display_t *display, igt_output_t *output) {
> +	igt_output_set_pipe(output, PIPE_NONE);
> +	igt_display_commit2(display, COMMIT_ATOMIC);
> +}
> +
>  static void check_writeback_fb_id(igt_output_t *output)
>  {
>  	uint64_t check_fb_id;
> @@ -449,6 +454,7 @@ igt_main
>  	}
>  
>  	igt_fixture {
> +		detach_crtc(&display, output);
>  		igt_remove_fb(display.drm_fd, &input_fb);
>  		igt_display_fini(&display);
>  	}
> -- 
> 2.31.0
>