rdp: Allow configuring the refresh rate

We currently hardcode a 60Hz update rate for the rdp backend.

In some cases it may be useful to override this to increase the rate
for a faster monitor, or to decrease it to reduce network traffic.

Co-authored-by: Steve Pronovost <spronovo@microsoft.com>
Co-authored-by: Brenton DeGeer <brdegeer@microsoft.com>
Signed-off-by: Hideyuki Nagase <hideyukn@microsoft.com>
Signed-off-by: Steve Pronovost <spronovo@microsoft.com>
Signed-off-by: Brenton DeGeer <brdegeer@microsoft.com>

compositor/main.c

@@ -2777,6 +2777,7 @@ weston_rdp_backend_config_init(struct weston_rdp_backend_config *config)
 	config->no_clients_resize = 0;
 	config->force_no_compression = 0;
 	config->remotefx_codec = true;
+	config->refresh_rate = RDP_DEFAULT_FREQ;
 }
 
 static int
@@ -2784,6 +2785,7 @@ load_rdp_backend(struct weston_compositor *c,
 		int *argc, char *argv[], struct weston_config *wc)
 {
 	struct weston_rdp_backend_config config  = {{ 0, }};
+	struct weston_config_section *section;
 	int ret = 0;
 	bool no_remotefx_codec = false;
 
@@ -2812,6 +2814,10 @@ load_rdp_backend(struct weston_compositor *c,
 	config.remotefx_codec = !no_remotefx_codec;
 
 	wet_set_simple_head_configurator(c, rdp_backend_output_configure);
+	section = weston_config_get_section(wc, "rdp", NULL, NULL);
+	weston_config_section_get_int(section, "refresh-rate",
+				      &config.refresh_rate,
+				      RDP_DEFAULT_FREQ);
 
 	ret = weston_compositor_load_backend(c, WESTON_BACKEND_RDP,
 					     &config.base);

include/libweston/backend-rdp.h

@@ -34,6 +34,7 @@ extern "C" {
 #include <libweston/plugin-registry.h>
 
 #define WESTON_RDP_OUTPUT_API_NAME "weston_rdp_output_api_v1"
+#define RDP_DEFAULT_FREQ 60
 
 struct weston_rdp_output_api {
 	/** Initialize a RDP output with specified width and height.
@@ -68,6 +69,7 @@ struct weston_rdp_backend_config {
 	int force_no_compression;
 	bool remotefx_codec;
 	int external_listener_fd;
+	int refresh_rate;
 };
 
 #ifdef  __cplusplus

libweston/backend-rdp/rdp.c

@@ -311,6 +311,7 @@ rdp_insert_new_mode(struct weston_output *output, int width, int height, int rat
 static struct weston_mode *
 ensure_matching_mode(struct weston_output *output, struct weston_mode *target)
 {
+	struct rdp_backend *b = to_rdp_backend(output->compositor);
 	struct weston_mode *local;
 
 	wl_list_for_each(local, &output->mode_list, link) {
@@ -318,7 +319,7 @@ ensure_matching_mode(struct weston_output *output, struct weston_mode *target)
 			return local;
 	}
 
-	return rdp_insert_new_mode(output, target->width, target->height, RDP_MODE_FREQ);
+	return rdp_insert_new_mode(output, target->width, target->height, b->rdp_monitor_refresh_rate);
 }
 
 static int
@@ -379,6 +380,7 @@ rdp_output_set_size(struct weston_output *base,
 		    int width, int height)
 {
 	struct rdp_output *output = to_rdp_output(base);
+	struct rdp_backend *rdpBackend = to_rdp_backend(base->compositor);
 	struct weston_head *head;
 	struct weston_mode *currentMode;
 	struct weston_mode initMode;
@@ -399,8 +401,7 @@ rdp_output_set_size(struct weston_output *base,
 	initMode.flags = WL_OUTPUT_MODE_CURRENT | WL_OUTPUT_MODE_PREFERRED;
 	initMode.width = width;
 	initMode.height = height;
-	initMode.refresh = RDP_MODE_FREQ;
+	initMode.refresh = rdpBackend->rdp_monitor_refresh_rate;
-
 	currentMode = ensure_matching_mode(&output->base, &initMode);
 	if (!currentMode)
 		return -1;
@@ -1370,6 +1371,9 @@ rdp_backend_create(struct weston_compositor *compositor,
 
 	/* After here, rdp_debug() is ready to be used */
 
+	b->rdp_monitor_refresh_rate = config->refresh_rate * 1000;
+	rdp_debug(b, "RDP backend: WESTON_RDP_MONITOR_REFRESH_RATE: %d\n", b->rdp_monitor_refresh_rate);
+
 	compositor->backend = &b->base;
 
 	if (config->server_cert && config->server_key) {
@@ -1485,6 +1489,7 @@ config_init_to_defaults(struct weston_rdp_backend_config *config)
 	config->force_no_compression = 0;
 	config->remotefx_codec = true;
 	config->external_listener_fd = -1;
+	config->refresh_rate = RDP_DEFAULT_FREQ;
 }
 
 WL_EXPORT int

libweston/backend-rdp/rdp.h

@@ -49,7 +49,6 @@
 
 #define MAX_FREERDP_FDS 32
 #define DEFAULT_AXIS_STEP_DISTANCE 10
-#define RDP_MODE_FREQ 60 * 1000
 #define DEFAULT_PIXEL_FORMAT PIXEL_FORMAT_BGRA32
 
 struct rdp_output;
@@ -72,6 +71,7 @@ struct rdp_backend {
 	int force_no_compression;
 	bool remotefx_codec;
 	int external_listener_fd;
+	int rdp_monitor_refresh_rate;
 };
 
 enum peer_item_flags {

man/weston-rdp.man

@@ -24,6 +24,19 @@ backend will announce security options based on which files have been given.
 The RDP backend is multi-seat aware, so if two clients connect on the backend,
 they will get their own seat.
 
+.\" ***************************************************************
+.SH CONFIGURATION
+.
+The RDP backend uses the following entries from
+.BR weston.ini .
+.SS Section rdp
+.TP
+\fBrefresh-rate\fR=\fIrate\fR
+Specifies the desktop redraw rate in Hz. If unspecified, the default is 60Hz. Changing
+this may be useful if you have a faster than 60Hz display, or if you want to reduce updates to
+reduce network traffic.
+
+
 .\" ***************************************************************
 .SH OPTIONS
 .