video: tegra: dc: Fix and refactor FRAME_END_INT

- Fix a conflict with other DC interrupt masks
  when the DSI driver waits on FRAME_END_INT
- Move generic FRAME_END_INT mask/unmask and
  wait-for functions to dc.c

Bug 1534724

Change-Id: I40e26ada2f0494782979e32c1a22906361b214b5
Signed-off-by: Daniel Solomon <daniels@nvidia.com>
Reviewed-on: http://git-master/r/451186
(cherry picked from commit 24a39c49f63eea704003ee27296f1f70d46bcbd0)
Reviewed-on: http://git-master/r/496580
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Jong Kim <jongk@nvidia.com>
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Tested-by: Bibek Basu <bbasu@nvidia.com>
Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>

4 files changed, 57 insertions, 32 deletions

diff --git a/drivers/video/tegra/dc/dc.c b/drivers/video/tegra/dc/dc.c
index 2809eef48ea3..541e6f00820f 100644
--- a/drivers/video/tegra/dc/dc.c
+++ b/drivers/video/tegra/dc/dc.c
@@ -1641,6 +1641,30 @@ int tegra_dc_wait_for_vsync(struct tegra_dc *dc)
 	return ret;
 }
 
+int tegra_dc_wait_for_frame_end(struct tegra_dc *dc,
+	u32 timeout_ms)
+{
+	int ret;
+
+	INIT_COMPLETION(dc->frame_end_complete);
+
+	tegra_dc_get(dc);
+
+	tegra_dc_flush_interrupt(dc, FRAME_END_INT);
+	/* unmask frame end interrupt */
+	tegra_dc_config_frame_end_intr(dc, true);
+
+	ret = wait_for_completion_interruptible_timeout(
+			&dc->frame_end_complete,
+			msecs_to_jiffies(timeout_ms));
+
+	tegra_dc_config_frame_end_intr(dc, false);
+
+	tegra_dc_put(dc);
+
+	return ret;
+}
+
 static void tegra_dc_prism_update_backlight(struct tegra_dc *dc)
 {
 	/* Do the actual brightness update outside of the mutex dc->lock */
@@ -1870,6 +1894,30 @@ static void tegra_dc_vpulse2(struct work_struct *work)
 }
 #endif
 
+int tegra_dc_config_frame_end_intr(struct tegra_dc *dc, bool enable)
+{
+	bool locked_by_caller;
+
+	/* This function is called in situations where dc->lock
+	 * is either free or already acquired - avoid a deadlock. */
+	locked_by_caller = mutex_is_locked(&dc->lock);
+	if (!locked_by_caller)
+		mutex_lock(&dc->lock);
+
+	tegra_dc_io_start(dc);
+	if (enable) {
+		atomic_inc(&dc->frame_end_ref);
+		tegra_dc_unmask_interrupt(dc, FRAME_END_INT);
+	} else if (!atomic_dec_return(&dc->frame_end_ref))
+		tegra_dc_mask_interrupt(dc, FRAME_END_INT);
+	tegra_dc_io_end(dc);
+
+	if (!locked_by_caller)
+		mutex_unlock(&dc->lock);
+
+	return 0;
+}
+
 static void tegra_dc_one_shot_irq(struct tegra_dc *dc, unsigned long status,
 		ktime_t timestamp)
 {
diff --git a/drivers/video/tegra/dc/dc_priv.h b/drivers/video/tegra/dc/dc_priv.h
index bf54bfffa7b8..1c5d53b92035 100644
--- a/drivers/video/tegra/dc/dc_priv.h
+++ b/drivers/video/tegra/dc/dc_priv.h
@@ -403,6 +403,13 @@ unsigned long tegra_dc_poll_register(struct tegra_dc *dc,
 u32 reg, u32 mask, u32 exp_val, u32 poll_interval_us,
 u32 timeout_ms);
 
+/* defined in dc.c, used in ext/dev.c */
+int tegra_dc_config_frame_end_intr(struct tegra_dc *dc, bool enable);
+
+/* defined in dc.c, used in dsi.c */
+int tegra_dc_wait_for_frame_end(struct tegra_dc *dc,
+	u32 timeout_ms);
+
 /* defined in bandwidth.c, used in dc.c */
 void tegra_dc_clear_bandwidth(struct tegra_dc *dc);
 void tegra_dc_program_bandwidth(struct tegra_dc *dc, bool use_new);
diff --git a/drivers/video/tegra/dc/dsi.c b/drivers/video/tegra/dc/dsi.c
index 681a63ce4bc6..df76712a5975 100644
--- a/drivers/video/tegra/dc/dsi.c
+++ b/drivers/video/tegra/dc/dsi.c
@@ -1694,7 +1694,6 @@ static int tegra_dsi_wait_frame_end(struct tegra_dc *dc,
 				struct tegra_dc_dsi_data *dsi,
 				u32 timeout_n_frames)
 {
-	int val;
 	long timeout;
 	u32 frame_period = DIV_ROUND_UP(S_TO_MS(1), dsi->info.refresh_rate);
 	struct tegra_dc_mode mode = dc->mode;
@@ -1707,26 +1706,12 @@ static int tegra_dsi_wait_frame_end(struct tegra_dc *dc,
 		dev_WARN(&dc->ndev->dev,
 		"dsi: to stop at next frame give at least 2 frame delay\n");
 
-	INIT_COMPLETION(dc->frame_end_complete);
-
-	tegra_dc_get(dc);
-
-	tegra_dc_flush_interrupt(dc, FRAME_END_INT);
-	/* unmask frame end interrupt */
-	val = tegra_dc_unmask_interrupt(dc, FRAME_END_INT);
-
-	timeout = wait_for_completion_interruptible_timeout(
-			&dc->frame_end_complete,
-			msecs_to_jiffies(timeout_n_frames * frame_period));
-
-	/* reinstate interrupt mask */
-	tegra_dc_writel(dc, val, DC_CMD_INT_MASK);
+	timeout = tegra_dc_wait_for_frame_end(dc, timeout_n_frames *
+		frame_period);
 
 	/* wait for v_ref_to_sync no. of lines after frame end interrupt */
 	udelay(mode.v_ref_to_sync * line_period);
 
-	tegra_dc_put(dc);
-
 	return timeout;
 }
 
diff --git a/drivers/video/tegra/dc/window.c b/drivers/video/tegra/dc/window.c
index ef8dd918a937..c7b44b182e67 100644
--- a/drivers/video/tegra/dc/window.c
+++ b/drivers/video/tegra/dc/window.c
@@ -49,21 +49,6 @@ static bool tegra_dc_windows_are_clean(struct tegra_dc_win *windows[],
 	return true;
 }
 
-int tegra_dc_config_frame_end_intr(struct tegra_dc *dc, bool enable)
-{
-
-	mutex_lock(&dc->lock);
-	tegra_dc_io_start(dc);
-	if (enable) {
-		atomic_inc(&dc->frame_end_ref);
-		tegra_dc_unmask_interrupt(dc, FRAME_END_INT);
-	} else if (!atomic_dec_return(&dc->frame_end_ref))
-		tegra_dc_mask_interrupt(dc, FRAME_END_INT);
-	tegra_dc_io_end(dc);
-	mutex_unlock(&dc->lock);
-	return 0;
-}
-
 static int get_topmost_window(u32 *depths, unsigned long *wins, int win_num)
 {
 	int idx, best = -1;