From f9d363fece0046cabfa00ad6b72b50f45b70db60 Mon Sep 17 00:00:00 2001
From: Scott Anderson <ascent12@hotmail.com>
Date: Sun, 14 May 2017 13:07:34 +1200
Subject: [PATCH] Added device matching

---
 backend/drm/backend.c         | 24 ++++++++++++++++++++----
 include/backend/drm/backend.h |  1 +
 include/wlr/session.h         |  7 +++++++
 session/logind.c              | 15 +++++++++++----
 4 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/backend/drm/backend.c b/backend/drm/backend.c
index e49197ec3..d8b7fc0ef 100644
--- a/backend/drm/backend.c
+++ b/backend/drm/backend.c
@@ -4,6 +4,7 @@
 #include <string.h>
 #include <errno.h>
 #include <wayland-server.h>
+#include <sys/stat.h>
 
 #include <wlr/session.h>
 #include <wlr/common/list.h>
@@ -38,23 +39,32 @@ static struct wlr_backend_impl backend_impl = {
 };
 
 static void device_paused(struct wl_listener *listener, void *data) {
-	struct wlr_backend_state *backend = wl_container_of(listener, backend, device_paused);
+	struct wlr_backend_state *drm = wl_container_of(listener, drm, device_paused);
+	struct device_arg *arg = data;
 
 	// TODO: Actually pause the renderer or something.
 	// We currently just expect it to fail its next pageflip.
 
-	(void)backend;
+	if (arg->dev == drm->dev) {
+		wlr_log(L_INFO, "DRM fd paused");
+	}
 }
 
 static void device_resumed(struct wl_listener *listener, void *data) {
 	struct wlr_backend_state *drm = wl_container_of(listener, drm, device_resumed);
-	int *new_fd = data;
+	struct device_arg *arg = data;
 
-	if (dup2(*new_fd, drm->fd) < 0) {
+	if (arg->dev != drm->dev) {
+		return;
+	}
+
+	if (dup2(arg->fd, drm->fd) < 0) {
 		wlr_log(L_ERROR, "dup2 failed: %s", strerror(errno));
 		return;
 	}
 
+	wlr_log(L_INFO, "DRM fd resumed");
+
 	for (size_t i = 0; i < drm->outputs->length; ++i) {
 		struct wlr_output_state *output = drm->outputs->items[i];
 		wlr_drm_output_start_renderer(output);
@@ -94,6 +104,12 @@ struct wlr_backend *wlr_drm_backend_create(struct wl_display *display,
 		goto error_udev;
 	}
 
+	struct stat st;
+	if (fstat(state->fd, &st) < 0) {
+		wlr_log(L_ERROR, "Stat failed: %s", strerror(errno));
+	}
+	state->dev = st.st_rdev;
+
 	struct wl_event_loop *event_loop = wl_display_get_event_loop(display);
 
 	state->drm_event = wl_event_loop_add_fd(event_loop, state->fd,
diff --git a/include/backend/drm/backend.h b/include/backend/drm/backend.h
index 4df86e214..e603bccdf 100644
--- a/include/backend/drm/backend.h
+++ b/include/backend/drm/backend.h
@@ -19,6 +19,7 @@
 
 struct wlr_backend_state {
 	int fd;
+	dev_t dev;
 
 	struct wlr_backend *backend;
 	struct wl_event_source *drm_event;
diff --git a/include/wlr/session.h b/include/wlr/session.h
index 4dfb026c2..5f210f101 100644
--- a/include/wlr/session.h
+++ b/include/wlr/session.h
@@ -2,9 +2,16 @@
 #define WLR_SESSION_H
 
 #include <wayland-server.h>
+#include <sys/types.h>
 
 struct session_interface;
 
+// Passed to the listeners of device_paused/resumed
+struct device_arg {
+	dev_t dev;
+	int fd; // Only for device_resumed
+};
+
 struct wlr_session {
 	const struct session_interface *iface;
 
diff --git a/session/logind.c b/session/logind.c
index b6763bf92..6f0327e62 100644
--- a/session/logind.c
+++ b/session/logind.c
@@ -198,8 +198,12 @@ static int pause_device(sd_bus_message *msg, void *userdata, sd_bus_error *ret_e
 		goto error;
 	}
 
-	dev_t dev = makedev(major, minor);
-	wl_signal_emit(&session->base.device_paused, &dev);
+	struct device_arg arg = {
+		.dev = makedev(major, minor),
+		.fd = -1,
+	};
+
+	wl_signal_emit(&session->base.device_paused, &arg);
 
 	ret = sd_bus_call_method(session->bus, "org.freedesktop.login1",
 		session->path, "org.freedesktop.login1.Session", "PauseDeviceComplete",
@@ -226,9 +230,12 @@ static int resume_device(sd_bus_message *msg, void *userdata, sd_bus_error *ret_
 		goto error;
 	}
 
-	// TODO: Use major/minor to make sure the right devices are getting signals
+	struct device_arg arg = {
+		.dev = makedev(major, minor),
+		.fd = fd,
+	};
 
-	wl_signal_emit(&session->base.device_resumed, &fd);
+	wl_signal_emit(&session->base.device_resumed, &arg);
 
 error:
 	return 0;