[PATCH] drm: kirin: Revert "Fix for hikey620 display offset problem"

[John Stultz]

This reverts commit ff57c6513820efe945b61863cf4a51b79f18b592.

With the commit ff57c6513820 ("drm: kirin: Fix for hikey620
display offset problem") we added support for handling LDI
overflows by resetting the hardware.

However, its been observed that when we do hit the LDI overflow
condition, the irq seems to be screaming, and we do nothing but
stream:
  [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow!
over and over to the screen

I've tried a few appraoches to avoid this, but none has yet
been successful and the cure here is worse then the original
disease, so revert this for now.

Cc: Xinliang Liu <z.liuxinliang at hisilicon.com>
Cc: Rongrong Zou <zourongrong at gmail.com>
Cc: Xinwei Kong <kong.kongxinwei at hisilicon.com>
Cc: Chen Feng <puck.chen at hisilicon.com>
Cc: Sam Ravnborg <sam at ravnborg.org>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: dri-devel <dri-devel at lists.freedesktop.org>
Fixes: ff57c6513820 ("drm: kirin: Fix for hikey620 display offset problem")
Signed-off-by: John Stultz <john.stultz at linaro.org>
---
 .../gpu/drm/hisilicon/kirin/kirin_ade_reg.h   |  1 -
 .../gpu/drm/hisilicon/kirin/kirin_drm_ade.c   | 20 -------------------
 2 files changed, 21 deletions(-)

diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_ade_reg.h b/drivers/gpu/drm/hisilicon/kirin/kirin_ade_reg.h
index 0da860200410..e2ac09894a6d 100644
--- a/drivers/gpu/drm/hisilicon/kirin/kirin_ade_reg.h
+++ b/drivers/gpu/drm/hisilicon/kirin/kirin_ade_reg.h
@@ -83,7 +83,6 @@
 #define VSIZE_OFST			20
 #define LDI_INT_EN			0x741C
 #define FRAME_END_INT_EN_OFST		1
-#define UNDERFLOW_INT_EN_OFST		2
 #define LDI_CTRL			0x7420
 #define BPP_OFST			3
 #define DATA_GATE_EN			BIT(2)
diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
index 73cd28a6ea07..86000127d4ee 100644
--- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
+++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
@@ -46,7 +46,6 @@ struct ade_hw_ctx {
 	struct clk *media_noc_clk;
 	struct clk *ade_pix_clk;
 	struct reset_control *reset;
-	struct work_struct display_reset_wq;
 	bool power_on;
 	int irq;
 
@@ -136,7 +135,6 @@ static void ade_init(struct ade_hw_ctx *ctx)
 	 */
 	ade_update_bits(base + ADE_CTRL, FRM_END_START_OFST,
 			FRM_END_START_MASK, REG_EFFECTIVE_IN_ADEEN_FRMEND);
-	ade_update_bits(base + LDI_INT_EN, UNDERFLOW_INT_EN_OFST, MASK(1), 1);
 }
 
 static bool ade_crtc_mode_fixup(struct drm_crtc *crtc,
@@ -304,17 +302,6 @@ static void ade_crtc_disable_vblank(struct drm_crtc *crtc)
 			MASK(1), 0);
 }
 
-static void drm_underflow_wq(struct work_struct *work)
-{
-	struct ade_hw_ctx *ctx = container_of(work, struct ade_hw_ctx,
-					      display_reset_wq);
-	struct drm_device *drm_dev = ctx->crtc->dev;
-	struct drm_atomic_state *state;
-
-	state = drm_atomic_helper_suspend(drm_dev);
-	drm_atomic_helper_resume(drm_dev, state);
-}
-
 static irqreturn_t ade_irq_handler(int irq, void *data)
 {
 	struct ade_hw_ctx *ctx = data;
@@ -331,12 +318,6 @@ static irqreturn_t ade_irq_handler(int irq, void *data)
 				MASK(1), 1);
 		drm_crtc_handle_vblank(crtc);
 	}
-	if (status & BIT(UNDERFLOW_INT_EN_OFST)) {
-		ade_update_bits(base + LDI_INT_CLR, UNDERFLOW_INT_EN_OFST,
-				MASK(1), 1);
-		DRM_ERROR("LDI underflow!");
-		schedule_work(&ctx->display_reset_wq);
-	}
 
 	return IRQ_HANDLED;
 }
@@ -919,7 +900,6 @@ static void *ade_hw_ctx_alloc(struct platform_device *pdev,
 	if (ret)
 		return ERR_PTR(-EIO);
 
-	INIT_WORK(&ctx->display_reset_wq, drm_underflow_wq);
 	ctx->crtc = crtc;
 
 	return ctx;
-- 
2.17.1