Commit db5be3a7 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Tomi Valkeinen
Browse files

drm: rcar-du: Ensure correct suspend/resume ordering with VSP 



The VSP serves as an interface to memory and a compositor to the DU. It
therefore needs to be suspended after and resumed before the DU, to be
properly stopped and restarted in a controlled fashion driven by the DU
driver. This currently works by chance. Avoid relying on luck by
enforcing the correct suspend/resume ordering with device links.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: default avatarBiju Das <biju.das.jz@bp.renesas.com>
Tested-by: default avatarTommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Reviewed-by: default avatarTommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Link: https://patch.msgid.link/20260323164526.2292491-2-laurent.pinchart+renesas@ideasonboard.com


Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ideasonboard.com>
parent d37690b5

drivers/gpu/drm/renesas/rcar-du/rcar_du_vsp.c

+16 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <drm/drm_vblank.h>



#include <linux/bitops.h>

#include <linux/device.h>

#include <linux/dma-mapping.h>

#include <linux/of_platform.h>

#include <linux/platform_device.h>
@@ -458,6 +459,9 @@ static void rcar_du_vsp_cleanup(struct drm_device *dev, void *res) 


	kfree(vsp->planes);



	if (vsp->link)

		device_link_del(vsp->link);



	put_device(vsp->vsp);

}
@@ -482,6 +486,18 @@ int rcar_du_vsp_init(struct rcar_du_vsp *vsp, struct device_node *np, 
	if (ret < 0)

		return ret;



	/*

	 * Enforce suspend/resume ordering between the DU (consumer) and the

	 * VSP (supplier). The DU will be suspended before and resume after the

	 * VSP.

	 */

	vsp->link = device_link_add(rcdu->dev, vsp->vsp, DL_FLAG_STATELESS);

	if (!vsp->link) {

		dev_err(rcdu->dev, "Failed to create device link to VSP %s\n",

			dev_name(vsp->vsp));

		return -EINVAL;

	}



	ret = vsp1_du_init(vsp->vsp);

	if (ret < 0)

		return ret;

drivers/gpu/drm/renesas/rcar-du/rcar_du_vsp.h

+2 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 


#include <drm/drm_plane.h>



struct device_link;

struct drm_framebuffer;

struct rcar_du_format_info;

struct rcar_du_vsp;
@@ -26,6 +27,7 @@ struct rcar_du_vsp_plane { 
struct rcar_du_vsp {

	unsigned int index;

	struct device *vsp;

	struct device_link *link;

	struct rcar_du_device *dev;

	struct rcar_du_vsp_plane *planes;

	unsigned int num_planes;