msm_fb: display: wake up system around vsync

To avoid frame drops due to power collapse,
wake up cpu right before vsync.

Conflicts:

	drivers/video/msm/mdp.c
	drivers/video/msm/msm_fb.h

Change-Id: I63385eb329ae5e74cbac5256823fd3a213e0a0e1
Signed-off-by: Ken Zhang <kenz@codeaurora.org>
Signed-off-by: Huaibin Yang <huaibiny@codeaurora.org>

drivers/video/msm/mdp.c

@@ -35,6 +35,7 @@
 #include <asm/mach-types.h>
 #include <linux/semaphore.h>
 #include <linux/uaccess.h>
+#include <mach/event_timer.h>
 #include <mach/clk.h>
 #include "mdp.h"
 #include "msm_fb.h"
@@ -1405,15 +1406,15 @@ int mdp_ppp_pipe_wait(void)
 	if (wait == TRUE) {
 		ret = wait_for_completion_interruptible_timeout(&mdp_ppp_comp,
 								5 * HZ);
-
 		if (!ret)
 			printk(KERN_ERR "%s: Timed out waiting for the MDP.\n",
-					__func__);
+				__func__);
 	}
 
 	return ret;
 }
 
+#define MAX_VSYNC_GAP		4
 #define DEFAULT_FRAME_RATE	60
 
 u32 mdp_get_panel_framerate(struct msm_fb_data_type *mfd)
@@ -1447,6 +1448,53 @@ u32 mdp_get_panel_framerate(struct msm_fb_data_type *mfd)
 	return frame_rate;
 }
 
+static int mdp_diff_to_next_vsync(ktime_t cur_time,
+			ktime_t last_vsync, u32 vsync_period)
+{
+	int diff_from_last, diff_to_next;
+	/*
+	 * Get interval beween last vsync and current time
+	 * Current time = CPU programming MDP for next Vsync
+	 */
+	diff_from_last =
+		(ktime_to_us(ktime_sub(cur_time, last_vsync)));
+	diff_from_last /= USEC_PER_MSEC;
+	/*
+	 * If the last Vsync occurred too long ago, skip programming
+	 * the timer
+	 */
+	if (diff_from_last < (vsync_period * MAX_VSYNC_GAP)) {
+		if (diff_from_last > vsync_period)
+			diff_to_next =
+				(diff_from_last - vsync_period) % vsync_period;
+		else
+			diff_to_next = vsync_period - diff_from_last;
+	} else {
+		/* mark it out of range */
+		diff_to_next = vsync_period + 1;
+	}
+	return diff_to_next;
+}
+
+void mdp_update_pm(struct msm_fb_data_type *mfd, ktime_t pre_vsync)
+{
+	u32 vsync_period;
+	int diff_to_next;
+	ktime_t cur_time, wakeup_time;
+
+	if (!mfd->cpu_pm_hdl)
+		return;
+	vsync_period = mfd->panel_info.frame_interval;
+	cur_time = ktime_get();
+	diff_to_next = mdp_diff_to_next_vsync(cur_time,
+					      pre_vsync,
+					      vsync_period);
+	if (diff_to_next > vsync_period)
+		return;
+	wakeup_time = ktime_add_ns(cur_time, diff_to_next * NSEC_PER_MSEC);
+	activate_event_timer(mfd->cpu_pm_hdl, wakeup_time);
+}
+
 static DEFINE_SPINLOCK(mdp_lock);
 static int mdp_irq_mask;
 static int mdp_irq_enabled;
@@ -2508,6 +2556,7 @@ static int mdp_probe(struct platform_device *pdev)
 	int rc;
 	resource_size_t  size ;
 	unsigned long flag;
+	u32 frame_rate;
 #ifdef CONFIG_FB_MSM_MDP40
 	int intf, if_no;
 #endif
@@ -2910,6 +2959,11 @@ static int mdp_probe(struct platform_device *pdev)
 		mdp_pipe_ctrl(MDP_CMD_BLOCK, MDP_BLOCK_POWER_OFF, FALSE);
 	}
 
+	frame_rate = mdp_get_panel_framerate(mfd);
+	if (frame_rate) {
+		mfd->panel_info.frame_interval = 1000 / frame_rate;
+		mfd->cpu_pm_hdl = add_event_timer(NULL, (void *)mfd);
+	}
 	mdp_clk_ctrl(0);
 
 #ifdef CONFIG_MSM_BUS_SCALING

drivers/video/msm/mdp.h

@@ -911,6 +911,7 @@ int mdp_ppp_v4l2_overlay_clear(void);
 int mdp_ppp_v4l2_overlay_play(struct fb_info *info,
 	unsigned long srcp0_addr, unsigned long srcp0_size,
 	unsigned long srcp1_addr, unsigned long srcp1_size);
+void mdp_update_pm(struct msm_fb_data_type *mfd, ktime_t pre_vsync);
 
 u32 mdp_get_panel_framerate(struct msm_fb_data_type *mfd);
 

drivers/video/msm/mdp4_overlay_atv.c

@@ -184,6 +184,8 @@ void mdp4_atv_overlay(struct msm_fb_data_type *mfd)
 	} else {
 		pipe->srcp0_addr = (uint32)(buf + buf_offset);
 	}
+	mdp_update_pm(mfd, vsync_ctrl_db[0].vsync_time);
+
 	mdp4_overlay_mdp_perf_req(pipe, mfd);
 	mdp4_overlay_mdp_perf_upd(mfd, 1);
 	mdp4_overlay_rgb_setup(pipe);

drivers/video/msm/mdp4_overlay_dsi_video.c

@@ -1132,6 +1132,7 @@ void mdp4_dsi_video_overlay(struct msm_fb_data_type *mfd)
 		mdp4_dsi_video_pipe_queue(0, pipe);
 	}
 
+	mdp_update_pm(mfd, vsync_ctrl_db[0].vsync_time);
 	mdp4_overlay_mdp_perf_upd(mfd, 1);
 
 	cnt = mdp4_dsi_video_pipe_commit(cndx, 0);

drivers/video/msm/mdp4_overlay_dtv.c

@@ -1068,6 +1068,7 @@ void mdp4_dtv_overlay(struct msm_fb_data_type *mfd)
 		pipe->srcp0_addr = (uint32)mfd->ibuf.buf;
 		mdp4_dtv_pipe_queue(0, pipe);
 	}
+	mdp_update_pm(mfd, vsync_ctrl_db[0].vsync_time);
 
 	mdp4_overlay_mdp_perf_upd(mfd, 1);
 	mdp4_dtv_pipe_commit(0, 0);

drivers/video/msm/mdp4_overlay_lcdc.c

@@ -971,6 +971,7 @@ void mdp4_lcdc_overlay(struct msm_fb_data_type *mfd)
 
 		mdp4_lcdc_pipe_queue(0, pipe);
 	}
+	mdp_update_pm(mfd, vsync_ctrl_db[0].vsync_time);
 
 	mdp4_overlay_mdp_perf_upd(mfd, 1);
 

drivers/video/msm/msm_fb.h

@@ -37,7 +37,6 @@
 #include <linux/fb.h>
 #include <linux/list.h>
 #include <linux/types.h>
-
 #include <linux/msm_mdp.h>
 #ifdef CONFIG_HAS_EARLYSUSPEND
 #include <linux/earlysuspend.h>
@@ -191,6 +190,7 @@ struct msm_fb_data_type {
 	u32 writeback_state;
 	bool writeback_active_cnt;
 	int cont_splash_done;
+	void *cpu_pm_hdl;
 	u32 acq_fen_cnt;
 	struct sync_fence *acq_fen[MDP_MAX_FENCE_FD];
 	int cur_rel_fen_fd;

drivers/video/msm/msm_fb_panel.h

@@ -169,7 +169,7 @@ struct msm_panel_info {
 	__u32 frame_count;
 	__u32 is_3d_panel;
 	__u32 frame_rate;
-
+	__u32 frame_interval;
 
 	struct mddi_panel_info mddi;
 	struct lcd_panel_info lcd;