[PATCH 1/2] drm/msm/mdp5: add tracking for clk enable-count

[PATCH 1/2] drm/msm/mdp5: add tracking for clk enable-count

[Rob Clark]

Accessing registers for an unclocked block is an insta-reboot on
snapdragon devices.  So add a bit of logic to track the enable_count so
we can WARN_ON() unclocked register writes.  This makes it much easier
to track down mistakes.

Signed-off-by: Rob Clark <robdclark@gmail.com>
---
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c | 5 +++++
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
index d3d6b4c..1189128 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
@@ -249,6 +249,9 @@ int mdp5_disable(struct mdp5_kms *mdp5_kms)
 {
 	DBG("");
 
+	mdp5_kms->enable_count--;
+	WARN_ON(mdp5_kms->enable_count < 0);
+
 	clk_disable_unprepare(mdp5_kms->ahb_clk);
 	clk_disable_unprepare(mdp5_kms->axi_clk);
 	clk_disable_unprepare(mdp5_kms->core_clk);
@@ -262,6 +265,8 @@ int mdp5_enable(struct mdp5_kms *mdp5_kms)
 {
 	DBG("");
 
+	mdp5_kms->enable_count++;
+
 	clk_prepare_enable(mdp5_kms->ahb_clk);
 	clk_prepare_enable(mdp5_kms->axi_clk);
 	clk_prepare_enable(mdp5_kms->core_clk);
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
index 8bdb7ee..c78faf0 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
@@ -80,6 +80,8 @@ struct mdp5_kms {
 	bool rpm_enabled;
 
 	struct mdp_irq error_handler;
+
+	int enable_count;
 };
 #define to_mdp5_kms(x) container_of(x, struct mdp5_kms, base)
 
@@ -171,11 +173,13 @@ struct mdp5_encoder {
 
 static inline void mdp5_write(struct mdp5_kms *mdp5_kms, u32 reg, u32 data)
 {
+	WARN_ON(mdp5_kms->enable_count <= 0);
 	msm_writel(data, mdp5_kms->mmio + reg);
 }
 
 static inline u32 mdp5_read(struct mdp5_kms *mdp5_kms, u32 reg)
 {
+	WARN_ON(mdp5_kms->enable_count <= 0);
 	return msm_readl(mdp5_kms->mmio + reg);
 }
 
-- 
2.9.4

[PATCH 2/2] drm/msm/mdp5: fix unclocked register access in _cursor_set()

[Rob Clark]

Fixes an insta-reboot when screen-blanking kicks in, due to cursor
updates without clocks enabled.

Signed-off-by: Rob Clark <robdclark@gmail.com>
---
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c
index 9217e0d..41a0775 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c
@@ -751,6 +751,7 @@ static int mdp5_crtc_cursor_set(struct drm_crtc *crtc,
 	if (!handle) {
 		DBG("Cursor off");
 		cursor_enable = false;
+		mdp5_enable(mdp5_kms);
 		goto set_cursor;
 	}
 
@@ -774,6 +775,8 @@ static int mdp5_crtc_cursor_set(struct drm_crtc *crtc,
 
 	get_roi(crtc, &roi_w, &roi_h);
 
+	mdp5_enable(mdp5_kms);
+
 	mdp5_write(mdp5_kms, REG_MDP5_LM_CURSOR_STRIDE(lm), stride);
 	mdp5_write(mdp5_kms, REG_MDP5_LM_CURSOR_FORMAT(lm),
 			MDP5_LM_CURSOR_FORMAT_FORMAT(CURSOR_FMT_ARGB8888));
@@ -802,6 +805,7 @@ static int mdp5_crtc_cursor_set(struct drm_crtc *crtc,
 	crtc_flush(crtc, flush_mask);
 
 end:
+	mdp5_disable(mdp5_kms);
 	if (old_bo) {
 		drm_flip_work_queue(&mdp5_crtc->unref_cursor_work, old_bo);
 		/* enable vblank to complete cursor work: */
@@ -834,6 +838,8 @@ static int mdp5_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
 
 	get_roi(crtc, &roi_w, &roi_h);
 
+	mdp5_enable(mdp5_kms);
+
 	spin_lock_irqsave(&mdp5_crtc->cursor.lock, flags);
 	mdp5_write(mdp5_kms, REG_MDP5_LM_CURSOR_SIZE(lm),
 			MDP5_LM_CURSOR_SIZE_ROI_H(roi_h) |
@@ -845,6 +851,8 @@ static int mdp5_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
 
 	crtc_flush(crtc, flush_mask);
 
+	mdp5_disable(mdp5_kms);
+
 	return 0;
 }
 
-- 
2.9.4