[PATCH] drm/vmwgfx: Trigger a modeset when the screen moves

[Maaz Mombasawala]

On 6/24/24 13:59, Ian Forbes wrote:
> When multi-monitor is cycled the X,Y position of the Screen Target will
> likely change but the resolution will not. We need to trigger a modeset
> when this occurs in order to recreate the Screen Target with the correct
> X,Y position.
> 
> Fixes a bug where multiple displays are shown in a single scrollable
> host window rather than in 2+ windows on separate host displays.
> 
> Fixes: 426826933109 ("drm/vmwgfx: Filter modes which exceed graphics memory")
> Signed-off-by: Ian Forbes <ian.forbes at broadcom.com>
> ---
>  drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c | 29 +++++++++++++++++++++++++++-
>  1 file changed, 28 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
> index a04e0736318da..9becd71bc93bc 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
> @@ -877,6 +877,32 @@ vmw_stdu_connector_mode_valid(struct drm_connector *connector,
>  	return MODE_OK;
>  }
>  
> +/*
> + * Trigger a modeset if the X,Y position of the Screen Target changes.
> + * This is needed when multi-mon is cycled. The original Screen Target will have
> + * the same mode but its relative X,Y position in the topology will change.
> + */
> +static int vmw_stdu_connector_atomic_check(struct drm_connector *conn,
> +					   struct drm_atomic_state *state)
> +{
> +	struct drm_connector_state *conn_state;
> +	struct vmw_screen_target_display_unit *du;
> +	struct drm_crtc_state *new_crtc_state;
> +
> +	conn_state = drm_atomic_get_connector_state(state, conn);
> +	du = vmw_connector_to_stdu(conn);
> +
> +	if (!conn_state->crtc)
> +		return 0;
> +
> +	new_crtc_state = drm_atomic_get_new_crtc_state(state, conn_state->crtc);

We should be checking for new_crtc_state being NULL here.

> +	if (du->base.gui_x != du->base.set_gui_x ||
> +	    du->base.gui_y != du->base.set_gui_y)
> +		new_crtc_state->mode_changed = true;
> +
> +	return 0;
> +}
> +
>  static const struct drm_connector_funcs vmw_stdu_connector_funcs = {
>  	.dpms = vmw_du_connector_dpms,
>  	.detect = vmw_du_connector_detect,
> @@ -891,7 +917,8 @@ static const struct drm_connector_funcs vmw_stdu_connector_funcs = {
>  static const struct
>  drm_connector_helper_funcs vmw_stdu_connector_helper_funcs = {
>  	.get_modes = vmw_connector_get_modes,
> -	.mode_valid = vmw_stdu_connector_mode_valid
> +	.mode_valid = vmw_stdu_connector_mode_valid,
> +	.atomic_check = vmw_stdu_connector_atomic_check,
>  };
>  
>  

Maaz Mombasawala <maaz.mombasawala at broadcom.com>