Commit 53ced169 authored by Laurent Pinchart's avatar Laurent Pinchart
Browse files

drm: rcar-du: Fix crash when using LVDS1 clock for CRTC 



On D3 and E3 platforms, the LVDS encoder includes a PLL that can
generate a clock for the corresponding CRTC, used even when the CRTC
output to a non-LVDS port. This mechanism is supported by the driver,
but the implementation is broken in dual-link LVDS mode. In that case,
the LVDS1 drm_encoder is skipped, which causes a crash when trying to
access its bridge later on.

Fix this by storing bridge pointers internally instead of retrieving
them from the encoder. The rcar_du_device encoders field isn't used
anymore and can be dropped.

Fixes: 8e8fddab ("drm: rcar-du: Skip LVDS1 output on Gen3 when using dual-link LVDS mode")
Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: default avatarJacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: default avatarKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
parent 2551952e

drivers/gpu/drm/rcar-du/rcar_du_crtc.c

+2 −8
Original line number Diff line number Diff line
@@ -730,13 +730,10 @@ static void rcar_du_crtc_atomic_enable(struct drm_crtc *crtc, 
	 */

	if (rcdu->info->lvds_clk_mask & BIT(rcrtc->index) &&

	    rstate->outputs == BIT(RCAR_DU_OUTPUT_DPAD0)) {

		struct rcar_du_encoder *encoder =

			rcdu->encoders[RCAR_DU_OUTPUT_LVDS0 + rcrtc->index];

		struct drm_bridge *bridge = rcdu->lvds[rcrtc->index];

		const struct drm_display_mode *mode =

			&crtc->state->adjusted_mode;

		struct drm_bridge *bridge;



		bridge = drm_bridge_chain_get_first_bridge(&encoder->base);

		rcar_lvds_clk_enable(bridge, mode->clock * 1000);

	}
@@ -764,15 +761,12 @@ static void rcar_du_crtc_atomic_disable(struct drm_crtc *crtc, 


	if (rcdu->info->lvds_clk_mask & BIT(rcrtc->index) &&

	    rstate->outputs == BIT(RCAR_DU_OUTPUT_DPAD0)) {

		struct rcar_du_encoder *encoder =

			rcdu->encoders[RCAR_DU_OUTPUT_LVDS0 + rcrtc->index];

		struct drm_bridge *bridge;

		struct drm_bridge *bridge = rcdu->lvds[rcrtc->index];



		/*

		 * Disable the LVDS clock output, see

		 * rcar_du_crtc_atomic_enable().

		 */

		bridge = drm_bridge_chain_get_first_bridge(&encoder->base);

		rcar_lvds_clk_disable(bridge);

	}

drivers/gpu/drm/rcar-du/rcar_du_drv.h

+3 −3
Original line number Diff line number Diff line
@@ -20,10 +20,10 @@ 


struct clk;

struct device;

struct drm_bridge;

struct drm_device;

struct drm_property;

struct rcar_du_device;

struct rcar_du_encoder;



#define RCAR_DU_FEATURE_CRTC_IRQ_CLOCK	BIT(0)	/* Per-CRTC IRQ and clock */

#define RCAR_DU_FEATURE_VSP1_SOURCE	BIT(1)	/* Has inputs from VSP1 */
@@ -71,6 +71,7 @@ struct rcar_du_device_info { 
#define RCAR_DU_MAX_CRTCS		4

#define RCAR_DU_MAX_GROUPS		DIV_ROUND_UP(RCAR_DU_MAX_CRTCS, 2)

#define RCAR_DU_MAX_VSPS		4

#define RCAR_DU_MAX_LVDS		2



struct rcar_du_device {

	struct device *dev;
@@ -83,11 +84,10 @@ struct rcar_du_device { 
	struct rcar_du_crtc crtcs[RCAR_DU_MAX_CRTCS];

	unsigned int num_crtcs;



	struct rcar_du_encoder *encoders[RCAR_DU_OUTPUT_MAX];



	struct rcar_du_group groups[RCAR_DU_MAX_GROUPS];

	struct platform_device *cmms[RCAR_DU_MAX_CRTCS];

	struct rcar_du_vsp vsps[RCAR_DU_MAX_VSPS];

	struct drm_bridge *lvds[RCAR_DU_MAX_LVDS];



	struct {

		struct drm_property *colorkey;

drivers/gpu/drm/rcar-du/rcar_du_encoder.c

+4 −1
Original line number Diff line number Diff line
@@ -57,7 +57,6 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, 
	if (renc == NULL)

		return -ENOMEM;



	rcdu->encoders[output] = renc;

	renc->output = output;

	encoder = rcar_encoder_to_drm_encoder(renc);
@@ -91,6 +90,10 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, 
			ret = -EPROBE_DEFER;

			goto done;

		}



		if (output == RCAR_DU_OUTPUT_LVDS0 ||

		    output == RCAR_DU_OUTPUT_LVDS1)

			rcdu->lvds[output - RCAR_DU_OUTPUT_LVDS0] = bridge;

	}



	/*