[PATCH 22/39] drm/imx: dc: Keep FU unit running on i.MX95

[Marek Vasut]

The i.MX95 does not have CF inputs into ED, it must pull inputs from FU
otherwise the controller crashes into green screen panic mode. Keep the
FU running on i.MX95.

Signed-off-by: Marek Vasut <marek.vasut at mailbox.org>
---
Cc: Abel Vesa <abelvesa at kernel.org>
Cc: Conor Dooley <conor+dt at kernel.org>
Cc: Fabio Estevam <festevam at gmail.com>
Cc: Krzysztof Kozlowski <krzk+dt at kernel.org>
Cc: Laurent Pinchart <Laurent.pinchart at ideasonboard.com>
Cc: Liu Ying <victor.liu at nxp.com>
Cc: Lucas Stach <l.stach at pengutronix.de>
Cc: Peng Fan <peng.fan at nxp.com>
Cc: Pengutronix Kernel Team <kernel at pengutronix.de>
Cc: Rob Herring <robh at kernel.org>
Cc: Shawn Guo <shawnguo at kernel.org>
Cc: Thomas Zimmermann <tzimmermann at suse.de>
Cc: devicetree at vger.kernel.org
Cc: dri-devel at lists.freedesktop.org
Cc: imx at lists.linux.dev
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-clk at vger.kernel.org
---
 drivers/gpu/drm/imx/dc/dc-kms.h   |  2 ++
 drivers/gpu/drm/imx/dc/dc-plane.c | 10 +++++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/imx/dc/dc-kms.h b/drivers/gpu/drm/imx/dc/dc-kms.h
index 3e61dbb87afe7..af37523ae0be3 100644
--- a/drivers/gpu/drm/imx/dc/dc-kms.h
+++ b/drivers/gpu/drm/imx/dc/dc-kms.h
@@ -130,6 +130,8 @@ struct dc_plane {
 	struct dc_lb *lb;
 	/** @ed: content stream extdst */
 	struct dc_ed *ed;
+	/** @keep_fu: keep FU running on iMX95 */
+	bool keep_fu;
 };
 
 #endif /* __DC_KMS_H__ */
diff --git a/drivers/gpu/drm/imx/dc/dc-plane.c b/drivers/gpu/drm/imx/dc/dc-plane.c
index d8b946fb90de6..18010c2b0bd78 100644
--- a/drivers/gpu/drm/imx/dc/dc-plane.c
+++ b/drivers/gpu/drm/imx/dc/dc-plane.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/container_of.h>
+#include <linux/of.h>
 
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
@@ -185,9 +186,11 @@ static void dc_plane_atomic_disable(struct drm_plane *plane,
 	if (!drm_dev_enter(plane->dev, &idx))
 		return;
 
-	/* disable fetchunit in shadow */
-	fu_ops = dc_fu_get_ops(dplane->fu);
-	fu_ops->disable_src_buf(dplane->fu, DC_FETCHUNIT_FRAC0);
+	/* disable fetchunit in shadow on i.MX8QXP */
+	if (!dplane->keep_fu) {
+		fu_ops = dc_fu_get_ops(dplane->fu);
+		fu_ops->disable_src_buf(dplane->fu, DC_FETCHUNIT_FRAC0);
+	}
 
 	/* set ExtDst's source to ConstFrame */
 	dc_ed_pec_src_sel(dplane->ed, dc_cf_get_link_id(dplane->cf));
@@ -219,6 +222,7 @@ int dc_plane_init(struct dc_drm_device *dc_drm, struct dc_plane *dc_plane)
 	dc_plane->cf = dc_drm->pe->cf_cont[plane->index];
 	dc_plane->lb = dc_drm->pe->lb[plane->index];
 	dc_plane->ed = dc_drm->pe->ed_cont[plane->index];
+	dc_plane->keep_fu = of_device_is_compatible(dc_drm->base.dev->of_node, "fsl,imx95-dc");
 
 	return 0;
 }
-- 
2.51.0