Re: [PATCH i-g-t 1/1] tests/kms_content_protection: Re-create framebuffer before each modeset

[Karthik B S <karthik.b.s@intel.com>]

Hi,

On 1/6/2026 3:51 PM, Jason-JH Lin wrote:
> The red and green framebuffers were previously created only once at
> the beginning of the test. If the test runs on multiple outputs with
> different resolutions, the pre-created framebuffer's size might not
> match the mode of a subsequent output, causing the modeset to fail.
I see that the test is already creating fb's considering the max 
width/height among of all the available outputs, so ideally this issue 
should not be hit. Are we seeing any actual failures which this patch 
fixes or just doing this as a fail safe?
>
> This patch moves the framebuffer creation logic inside the
> modeset_with_fb() function. This ensures that for every modeset
> operation, a new framebuffer is created with dimensions that
> perfectly match the current output's mode, preventing potential
> modeset failures on systems with multiple displays of varying
> resolutions.

If we indeed see the issue and go ahead with this patch, fb cleanups 
need to be handled for the additional fb's created. Currently we are 
doing fb cleanup only once at the end of the test.

Also we need to remove the existing fb creation as it becomes redundant 
with this change?

Regards,
Karthik.B.S
>
> Signed-off-by: Jason-JH Lin <jason-jh.lin@mediatek.com>
> ---
>   tests/kms_content_protection.c | 7 +++++++
>   1 file changed, 7 insertions(+)
>
> diff --git a/tests/kms_content_protection.c b/tests/kms_content_protection.c
> index 377bab9a3afb..980091871679 100644
> --- a/tests/kms_content_protection.c
> +++ b/tests/kms_content_protection.c
> @@ -250,6 +250,13 @@ static void modeset_with_fb(const enum pipe pipe, igt_output_t *output,
>   
>   	mode = igt_output_get_mode(output);
>   
> +	igt_create_color_fb(data.drm_fd, mode->hdisplay, mode->vdisplay,
> +			    DRM_FORMAT_XRGB8888, DRM_FORMAT_MOD_LINEAR,
> +			    1.f, 0.f, 0.f, &data.red);
> +	igt_create_color_fb(data.drm_fd, mode->hdisplay, mode->vdisplay,
> +			    DRM_FORMAT_XRGB8888, DRM_FORMAT_MOD_LINEAR,
> +			    0.f, 1.f, 0.f, &data.green);
> +
>   	primary = igt_output_get_plane_type(output, DRM_PLANE_TYPE_PRIMARY);
>   	igt_plane_set_fb(primary, &data.red);
>   	igt_fb_set_size(&data.red, primary, mode->hdisplay, mode->vdisplay);