intel_fb: enable polling for connector changes

To circumvent problems on platforms with shaky hotplug interrupt notification
introduce a "poll" configuration option to the driver, which enables
polling for connector changes.

Fix #2004

repos/dde_linux/src/drivers/framebuffer/intel/README

@@ -35,6 +35,15 @@ configuration like this:
 
 ! <config buffered="yes"/>
 
+If you experience problems like hotplugging of connectors does not work, you
+can force the driver to poll frequently for hotplug events by defining a period
+in milliseconds like this:
+
+! <config poll="1000"/>
+
+If you define a period of zero, the driver won't poll at all, which is the
+default value.
+
 To present all available connectors and their possible resolutions to the user
 the driver is able to export a corresponding report ROM. This has to be
 configured too, like in the following:

repos/dde_linux/src/drivers/framebuffer/intel/include/component.h

@@ -15,6 +15,7 @@
 #define __COMPONENT_H__
 
 /* Genode includes */
+#include <base/component.h>
 #include <base/rpc_server.h>
 #include <root/component.h>
 #include <dataspace/capability.h>
@@ -41,21 +42,28 @@ class Framebuffer::Driver
 {
 	private:
 
-		Session_component        &_session;
-		int                       _height          = 0;
-		int                       _width           = 0;
-		static constexpr unsigned _bytes_per_pixel = 2;
-		void                     *_new_fb_ds_base  = nullptr;
-		void                     *_cur_fb_ds_base  = nullptr;
-		Genode::uint64_t          _cur_fb_ds_size  = 0;
-		drm_framebuffer          *_new_fb          = nullptr;
-		drm_framebuffer          *_cur_fb          = nullptr;
+		Session_component             &_session;
+		Timer::Connection              _timer;
+		Genode::Signal_handler<Driver> _poll_handler;
+		int                            _height          = 0;
+		int                            _width           = 0;
+		static constexpr unsigned      _bytes_per_pixel = 2;
+		void                          *_new_fb_ds_base  = nullptr;
+		void                          *_cur_fb_ds_base  = nullptr;
+		Genode::uint64_t               _cur_fb_ds_size  = 0;
+		drm_framebuffer               *_new_fb          = nullptr;
+		drm_framebuffer               *_cur_fb          = nullptr;
+		unsigned long                  _poll_ms         = false;
 
 		drm_display_mode * _preferred_mode(drm_connector *connector);
 
+		void _poll();
+
 	public:
 
-		Driver(Session_component &session) : _session(session) {}
+		Driver(Genode::Env & env, Session_component &session)
+		: _session(session), _timer(env),
+		  _poll_handler(env.ep(), *this, &Driver::_poll) {}
 
 		int      width()  const { return _width;           }
 		int      height() const { return _height;          }
@@ -65,6 +73,7 @@ class Framebuffer::Driver
 			return _width * _height * _bytes_per_pixel; }
 
 		void finish_initialization();
+		void set_polling(unsigned long poll);
 		bool mode_changed();
 		void generate_report();
 		void free_framebuffer();
@@ -90,6 +99,9 @@ class Framebuffer::Session_component : public Genode::Rpc_object<Session>
 		bool _buffered_from_config() {
 			return _config.xml().attribute_value("buffered", false); }
 
+		unsigned long _polling_from_config() {
+			return _config.xml().attribute_value<unsigned long>("poll", 0); }
+
 		void _refresh_buffered(int x, int y, int w, int h)
 		{
 			using namespace Genode;
@@ -114,8 +126,9 @@ class Framebuffer::Session_component : public Genode::Rpc_object<Session>
 
 	public:
 
-		Session_component(Genode::Attached_rom_dataspace &config)
-		: _driver(*this), _config(config),
+		Session_component(Genode::Env &env,
+		                  Genode::Attached_rom_dataspace &config)
+		: _driver(env, *this), _config(config), _timer(env),
 		  _buffered(_buffered_from_config()) {}
 
 		Driver & driver() { return _driver; }
@@ -127,6 +140,7 @@ class Framebuffer::Session_component : public Genode::Rpc_object<Session>
 
 			_in_update = true;
 			_buffered  = _buffered_from_config();
+			_driver.set_polling(_polling_from_config());
 			if (_driver.mode_changed() && _mode_sigh.valid())
 				Genode::Signal_transmitter(_mode_sigh).submit();
 			else
@@ -191,11 +205,11 @@ struct Framebuffer::Root
 	Session_component *_create_session(const char *args) override {
 		return &session; }
 
-	Root(Genode::Entrypoint &ep, Genode::Allocator &alloc,
+	Root(Genode::Env &env, Genode::Allocator &alloc,
 	     Genode::Attached_rom_dataspace &config)
 	: Genode::Root_component<Session_component,
-	                         Genode::Single_client>(ep, alloc),
-	  session(config) { }
+	                         Genode::Single_client>(env.ep(), alloc),
+	  session(env, config) { }
 };
 
 #endif /* __COMPONENT_H__ */

repos/dde_linux/src/drivers/framebuffer/intel/lx_emul.cc

@@ -137,9 +137,34 @@ void Framebuffer::Driver::finish_initialization()
 {
 	dde_c_set_driver(dde_drm_device, (void*)this);
 	generate_report();
-	mode_changed();
+	_session.config_changed();
 }
 
+
+#include <lx_kit/irq.h>
+
+void Framebuffer::Driver::_poll()
+{
+	Lx::Pci_dev * pci_dev = (Lx::Pci_dev*) dde_drm_device->pdev->bus;
+	Lx::Irq::irq().inject_irq(pci_dev->client());
+}
+
+
+void Framebuffer::Driver::set_polling(unsigned long poll)
+{
+	if (poll == _poll_ms) return;
+
+	_poll_ms = poll;
+
+	if (_poll_ms) {
+		_timer.sigh(_poll_handler);
+		_timer.trigger_periodic(_poll_ms * 1000);
+	} else {
+		_timer.sigh(Genode::Signal_context_capability());
+	}
+}
+
+
 bool Framebuffer::Driver::mode_changed()
 {
 	using namespace Genode;
@@ -920,8 +945,6 @@ int drm_get_pci_dev(struct pci_dev *pdev, const struct pci_device_id *ent,
 }
 
 
-#include <lx_kit/irq.h>
-
 int request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
                 const char *name, void *dev)
 {

repos/dde_linux/src/drivers/framebuffer/intel/main.cc

@@ -41,11 +41,11 @@ unsigned long jiffies;
 
 struct Main
 {
-	Genode::Entrypoint            &ep;
-	Genode::Attached_rom_dataspace config;
-	Genode::Heap                   heap;
-
-	Framebuffer::Root root { ep, heap, config };
+	Genode::Env                   &env;
+	Genode::Entrypoint            &ep     { env.ep() };
+	Genode::Attached_rom_dataspace config { env, "config" };
+	Genode::Heap                   heap   { env.ram(), env.rm() };
+	Framebuffer::Root              root   { env, heap, config };
 
 	/* init singleton Lx::Timer */
 	Lx::Timer &timer = Lx::timer(&ep, &jiffies);
@@ -60,8 +60,7 @@ struct Main
 	Lx::Task linux { run_linux, reinterpret_cast<void*>(this), "linux",
 	                 Lx::Task::PRIORITY_0, Lx::scheduler() };
 
-	Main(Genode::Env &env)
-	: ep(env.ep()), config(env, "config"), heap(env.ram(), env.rm())
+	Main(Genode::Env &env) : env(env)
 	{
 		Genode::log("--- intel framebuffer driver ---");
 

repos/dde_linux/src/include/lx_kit/irq.h

@@ -35,6 +35,8 @@ class Lx::Irq
 		 */
 		virtual void request_irq(Platform::Device &dev, irq_handler_t handler,
 		                         void *dev_id, irq_handler_t thread_fn = 0) = 0;
+
+		virtual void inject_irq(Platform::Device &dev) = 0;
 };
 
 #endif /* _LX_KIT__IRQ_H_ */

repos/dde_linux/src/lx_kit/irq.cc

@@ -96,18 +96,7 @@ class Lx_kit::Irq : public Lx::Irq
 				Lx_kit::List<Handler>       _handler;
 				Lx::Task                    _task;
 
-				Genode::Signal_rpc_member<Context> _dispatcher;
-
-				/**
-				 * Signal handler
-				 */
-				void _handle(unsigned)
-				{
-					_task.unblock();
-
-					/* kick off scheduling */
-					Lx::scheduler().schedule();
-				}
+				Genode::Signal_handler<Context> _dispatcher;
 
 				static void _run_irq(void *args)
 				{
@@ -131,7 +120,7 @@ class Lx_kit::Irq : public Lx::Irq
 					_dev(dev),
 					_irq_sess(dev.irq(0)),
 					_task(_run_irq, this, _name.name, Lx::Task::PRIORITY_3, Lx::scheduler()),
-					_dispatcher(ep, *this, &Context::_handle)
+					_dispatcher(ep, *this, &Context::unblock)
 				{
 					_irq_sess.sigh(_dispatcher);
 
@@ -139,6 +128,17 @@ class Lx_kit::Irq : public Lx::Irq
 					_irq_sess.ack_irq();
 				}
 
+				/**
+				 * Unblock this context, e.g., as result of an IRQ signal
+				 */
+				void unblock()
+				{
+					_task.unblock();
+
+					/* kick off scheduling */
+					Lx::scheduler().schedule();
+				}
+
 				/**
 				 * Handle IRQ
 				 */
@@ -214,6 +214,12 @@ class Lx_kit::Irq : public Lx::Irq
 			                   Handler(dev_id, handler, thread_fn);
 			ctx->add_handler(h);
 		}
+
+		void inject_irq(Platform::Device &dev)
+		{
+			Context *ctx = _find_context(dev);
+			if (ctx) ctx->unblock();
+		}
 };