POC framebuffer/de: use vblank interrupt

Issue genodelabs#23.

ports/a64_linux.hash

@@ -1 +1 @@
-c552684c04213913e5a85fb40ed3b9220eb26d36
+e0aa081d0d5397b038c4be565bf879f5615d6fd1

ports/a64_linux.port

@@ -10,7 +10,9 @@ DIR(a64_linux) := src/linux
 PATCHES := \
            src/a64_linux/csi_ov5640_pm.patch \
            src/a64_linux/remove_usbphy_role_switch.patch \
-           src/a64_linux/usb_message.patch
+           src/a64_linux/usb_message.patch \
+           src/a64_linux/drm_vblank.patch
+
 
 #
 # Just to make sure that the compiler will use the right header files

src/a64_linux/drm_vblank.patch

@@ -0,0 +1,30 @@
+--- src/linux/drivers/gpu/drm/drm_vblank.c
++++ src/linux/drivers/gpu/drm/drm_vblank.c
+@@ -159,7 +159,7 @@ drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
+
+ static unsigned int drm_timestamp_precision = 20;  /* Default to 20 usecs. */
+
+-static int drm_vblank_offdelay = 5000;    /* Default to 5000 msecs. */
++static int drm_vblank_offdelay = 0000;    /* Default to 5000 msecs. */
+
+ module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
+ module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
+--- src/linux/drivers/gpu/drm/sun4i/sun4i_tcon.c
++++ src/linux/drivers/gpu/drm/sun4i/sun4i_tcon.c
+@@ -791,6 +791,8 @@ static void sun4i_tcon_finish_page_flip(struct drm_device *dev,
+ 	spin_unlock_irqrestore(&dev->event_lock, flags);
+ }
+
++extern void lx_emul_framebuffer_vblank(void);
++
+ static irqreturn_t sun4i_tcon_handler(int irq, void *private)
+ {
+ 	struct sun4i_tcon *tcon = private;
+@@ -807,6 +809,7 @@ static irqreturn_t sun4i_tcon_handler(int irq, void *private)
+ 		return IRQ_NONE;
+
+ 	drm_crtc_handle_vblank(&scrtc->crtc);
++	lx_emul_framebuffer_vblank();
+ 	sun4i_tcon_finish_page_flip(drm, scrtc);
+
+ 	/* Acknowledge the interrupt */

src/drivers/framebuffer/de/main.cc

@@ -70,6 +70,13 @@ struct Framebuffer::Driver
 
 	void handle_timer()
 	{
+#if 0
+		static Genode::Milliseconds last_ms = timer.curr_time().trunc_to_plain_ms();
+		Genode::Milliseconds ms = timer.curr_time().trunc_to_plain_ms();
+		Genode::error(__func__, ": diff: ", ms.value - last_ms.value);
+		last_ms = ms;
+#endif
+
 		if (fb.constructed()) { fb->paint(); }
 	}
 
@@ -88,9 +95,6 @@ struct Framebuffer::Driver
 
 		lx_emul_start_kernel(dtb_rom.local_addr<void>());
 		log("returned from lx_emul_start_kernel");
-
-		timer.sigh(timer_handler);
-		timer.trigger_periodic(20*1000);
 	}
 };
 
@@ -102,6 +106,13 @@ static Framebuffer::Driver & driver(Genode::Env & env)
 }
 
 
+extern "C" void lx_emul_framebuffer_vblank(void)
+{
+	Genode::Env & env = Lx_kit::env().env;
+	driver(env).handle_timer();
+}
+
+
 /**
  * Can be called already as side-effect of `lx_emul_start_kernel`,
  * that's why the Driver object needs to be constructed already here.
@@ -111,6 +122,7 @@ extern "C" void lx_emul_framebuffer_ready(void * base, unsigned long,
 {
 	Genode::Env & env = Lx_kit::env().env;
 	driver(env).fb.construct(env, base, xres, yres);
+	driver(env).handle_timer();
 
 	Genode::log("--- framebuffer driver initialized ---");
 }