disp: msm: sde: Add check to avoid list double add

When LTM hist disable and LTM queue buffer are both queued to driver
in the same commit, if LTM hist disable call is handled by driver first,
all the LTM hist buffers will be moved to buffer_free list. When LTM
queue buffer call is handled, it will try to add the same buffer
to the buffer_free list again, and cause a list double add error.
This change checks if the buffer is already in the buffer_free list
before adding.

Change-Id: I74debdede551ceacfa2735fdb327a37654ad70f7
Signed-off-by: Ping Li <[email protected]>

msm/sde/sde_color_processing.c

@@ -2787,8 +2787,9 @@ static void _sde_cp_crtc_queue_ltm_buffer(struct sde_crtc *sde_crtc, void *cfg)
 	struct drm_msm_ltm_buffer *buf;
 	struct drm_msm_ltm_stats_data *ltm_data = NULL;
 	u32 i;
-	bool found = false;
+	bool found = false, already = false;
 	unsigned long irq_flags;
+	struct sde_ltm_buffer *buffer = NULL, *n = NULL;
 
 	if (!sde_crtc || !cfg) {
 		DRM_ERROR("invalid parameters sde_crtc %pK cfg %pK\n", sde_crtc,
@@ -2818,7 +2819,13 @@ static void _sde_cp_crtc_queue_ltm_buffer(struct sde_crtc *sde_crtc, void *cfg)
 				 sde_crtc->ltm_buffers[i]->offset);
 			ltm_data->status_flag = 0;
 
-			list_add_tail(&sde_crtc->ltm_buffers[i]->node,
+			list_for_each_entry_safe(buffer, n,
+					&sde_crtc->ltm_buf_free, node) {
+				if (buffer->drm_fb_id == buf->fd)
+					already =  true;
+			}
+			if (!already)
+				list_add_tail(&sde_crtc->ltm_buffers[i]->node,
 					&sde_crtc->ltm_buf_free);
 			found = true;
 		}
@@ -2970,6 +2977,7 @@ static void sde_cp_ltm_hist_interrupt_cb(void *arg, int irq_idx)
 		}
 
 		spin_unlock_irqrestore(&sde_crtc->ltm_lock, irq_flags);
+		DRM_DEBUG_DRIVER("LTM histogram is disabled\n");
 		return;
 	}
 
@@ -3019,6 +3027,7 @@ static void sde_cp_ltm_hist_interrupt_cb(void *arg, int irq_idx)
 
 	hw_lm = sde_crtc->mixers[0].hw_lm;
 	if (!hw_lm) {
+		spin_unlock_irqrestore(&sde_crtc->ltm_lock, irq_flags);
 		DRM_ERROR("invalid layer mixer\n");
 		return;
 	}
@@ -3085,6 +3094,7 @@ static void sde_cp_notify_ltm_hist(struct drm_crtc *crtc, void *arg)
 		/* histogram is disabled, no need to notify user space */
 		spin_unlock_irqrestore(&sde_crtc->ltm_lock, irq_flags);
 		mutex_unlock(&sde_crtc->ltm_buffer_lock);
+		DRM_DEBUG_DRIVER("ltm histogram is disabled\n");
 		return;
 	}
 
@@ -3093,6 +3103,8 @@ static void sde_cp_notify_ltm_hist(struct drm_crtc *crtc, void *arg)
 	payload.offset = buf->offset;
 	event.length = sizeof(struct drm_msm_ltm_buffer);
 	event.type = DRM_EVENT_LTM_HIST;
+	DRM_DEBUG_DRIVER("notify with LTM hist event drm_fb_id %d\n",
+				buf->drm_fb_id);
 	msm_mode_object_event_notify(&crtc->base, crtc->dev, &event,
 					(u8 *)&payload);
 	spin_unlock_irqrestore(&sde_crtc->ltm_lock, irq_flags);