* [PATCH v5] display/gtk: get proper refreshrate
@ 2020-01-08 12:13 pavlica.nikola
2020-01-08 14:54 ` Philippe Mathieu-Daudé
2020-01-09 13:21 ` Gerd Hoffmann
0 siblings, 2 replies; 3+ messages in thread
From: pavlica.nikola @ 2020-01-08 12:13 UTC (permalink / raw)
To: qemu-devel; +Cc: kraxel, Nikola Pavlica
From: Nikola Pavlica <pavlica.nikola@gmail.com>
Because some VMs in QEMU can get GPU virtualization (using technologies
such as iGVT-g, as mentioned previously), they could produce a video
output that had a higher display refresh rate than of what the GTK
display was displaying. (fxp. Playing a video game inside of a Windows
VM at 60 Hz, while the output stood locked at 33 Hz because of defaults
set in include/ui/console.h)
Since QEMU does indeed have internal systems for determining frame
times as defined in ui/console.c.
The code checks for a variable called update_interval that it later
uses for time calculation. This variable, however, isn't defined
anywhere in ui/gtk.c and instead ui/console.c just sets it to
GUI_REFRESH_INTERVAL_DEFAULT which is 30
update_interval represents the number of milliseconds per display
refresh, and by doing some math we get that 1000/30 = 33.33... Hz
This creates the mentioned problem and what this patch does is that it
checks for the display refresh rate reported by GTK itself (we can take
this as a safe value) and just converts it back to a number of
milliseconds per display refresh.
Signed-off-by: Nikola Pavlica <pavlica.nikola@gmail.com>
---
include/ui/gtk.h | 2 ++
ui/gtk.c | 10 ++++++++++
2 files changed, 12 insertions(+)
diff --git a/include/ui/gtk.h b/include/ui/gtk.h
index d9eedad976..d1b230848a 100644
--- a/include/ui/gtk.h
+++ b/include/ui/gtk.h
@@ -28,6 +28,8 @@
#include "ui/egl-context.h"
#endif
+#define MILLISEC_PER_SEC 1000000
+
typedef struct GtkDisplayState GtkDisplayState;
typedef struct VirtualGfxConsole {
diff --git a/ui/gtk.c b/ui/gtk.c
index 692ccc7bbb..eb0efc70ee 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -1966,6 +1966,10 @@ static GSList *gd_vc_gfx_init(GtkDisplayState *s, VirtualConsole *vc,
GSList *group, GtkWidget *view_menu)
{
bool zoom_to_fit = false;
+ int refresh_rate_millihz;
+ GdkDisplay *dpy = gtk_widget_get_display(s->window);
+ GdkWindow *win = gtk_widget_get_window(s->window);
+ GdkMonitor *monitor = gdk_display_get_monitor_at_window(dpy, win);
vc->label = qemu_console_get_label(con);
vc->s = s;
@@ -2026,6 +2030,12 @@ static GSList *gd_vc_gfx_init(GtkDisplayState *s, VirtualConsole *vc,
vc->gfx.kbd = qkbd_state_init(con);
vc->gfx.dcl.con = con;
+
+ refresh_rate_millihz = gdk_monitor_get_refresh_rate(monitor);
+ if (refresh_rate_millihz) {
+ vc->gfx.dcl.update_interval = MILLISEC_PER_SEC / refresh_rate_millihz;
+ }
+
register_displaychangelistener(&vc->gfx.dcl);
gd_connect_vc_gfx_signals(vc);
--
2.24.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v5] display/gtk: get proper refreshrate
2020-01-08 12:13 [PATCH v5] display/gtk: get proper refreshrate pavlica.nikola
@ 2020-01-08 14:54 ` Philippe Mathieu-Daudé
2020-01-09 13:21 ` Gerd Hoffmann
1 sibling, 0 replies; 3+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-01-08 14:54 UTC (permalink / raw)
To: pavlica.nikola, qemu-devel; +Cc: kraxel
On 1/8/20 1:13 PM, pavlica.nikola@gmail.com wrote:
> From: Nikola Pavlica <pavlica.nikola@gmail.com>
>
> Because some VMs in QEMU can get GPU virtualization (using technologies
> such as iGVT-g, as mentioned previously), they could produce a video
> output that had a higher display refresh rate than of what the GTK
> display was displaying. (fxp. Playing a video game inside of a Windows
> VM at 60 Hz, while the output stood locked at 33 Hz because of defaults
> set in include/ui/console.h)
>
> Since QEMU does indeed have internal systems for determining frame
> times as defined in ui/console.c.
> The code checks for a variable called update_interval that it later
> uses for time calculation. This variable, however, isn't defined
> anywhere in ui/gtk.c and instead ui/console.c just sets it to
> GUI_REFRESH_INTERVAL_DEFAULT which is 30
>
> update_interval represents the number of milliseconds per display
> refresh, and by doing some math we get that 1000/30 = 33.33... Hz
>
> This creates the mentioned problem and what this patch does is that it
> checks for the display refresh rate reported by GTK itself (we can take
> this as a safe value) and just converts it back to a number of
> milliseconds per display refresh.
>
> Signed-off-by: Nikola Pavlica <pavlica.nikola@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> include/ui/gtk.h | 2 ++
> ui/gtk.c | 10 ++++++++++
> 2 files changed, 12 insertions(+)
>
> diff --git a/include/ui/gtk.h b/include/ui/gtk.h
> index d9eedad976..d1b230848a 100644
> --- a/include/ui/gtk.h
> +++ b/include/ui/gtk.h
> @@ -28,6 +28,8 @@
> #include "ui/egl-context.h"
> #endif
>
> +#define MILLISEC_PER_SEC 1000000
> +
> typedef struct GtkDisplayState GtkDisplayState;
>
> typedef struct VirtualGfxConsole {
> diff --git a/ui/gtk.c b/ui/gtk.c
> index 692ccc7bbb..eb0efc70ee 100644
> --- a/ui/gtk.c
> +++ b/ui/gtk.c
> @@ -1966,6 +1966,10 @@ static GSList *gd_vc_gfx_init(GtkDisplayState *s, VirtualConsole *vc,
> GSList *group, GtkWidget *view_menu)
> {
> bool zoom_to_fit = false;
> + int refresh_rate_millihz;
> + GdkDisplay *dpy = gtk_widget_get_display(s->window);
> + GdkWindow *win = gtk_widget_get_window(s->window);
> + GdkMonitor *monitor = gdk_display_get_monitor_at_window(dpy, win);
>
> vc->label = qemu_console_get_label(con);
> vc->s = s;
> @@ -2026,6 +2030,12 @@ static GSList *gd_vc_gfx_init(GtkDisplayState *s, VirtualConsole *vc,
>
> vc->gfx.kbd = qkbd_state_init(con);
> vc->gfx.dcl.con = con;
> +
> + refresh_rate_millihz = gdk_monitor_get_refresh_rate(monitor);
> + if (refresh_rate_millihz) {
> + vc->gfx.dcl.update_interval = MILLISEC_PER_SEC / refresh_rate_millihz;
> + }
> +
> register_displaychangelistener(&vc->gfx.dcl);
>
> gd_connect_vc_gfx_signals(vc);
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v5] display/gtk: get proper refreshrate
2020-01-08 12:13 [PATCH v5] display/gtk: get proper refreshrate pavlica.nikola
2020-01-08 14:54 ` Philippe Mathieu-Daudé
@ 2020-01-09 13:21 ` Gerd Hoffmann
1 sibling, 0 replies; 3+ messages in thread
From: Gerd Hoffmann @ 2020-01-09 13:21 UTC (permalink / raw)
To: pavlica.nikola; +Cc: qemu-devel
On Wed, Jan 08, 2020 at 01:13:42PM +0100, pavlica.nikola@gmail.com wrote:
> From: Nikola Pavlica <pavlica.nikola@gmail.com>
>
> Because some VMs in QEMU can get GPU virtualization (using technologies
> such as iGVT-g, as mentioned previously), they could produce a video
> output that had a higher display refresh rate than of what the GTK
> display was displaying. (fxp. Playing a video game inside of a Windows
> VM at 60 Hz, while the output stood locked at 33 Hz because of defaults
> set in include/ui/console.h)
>
> Since QEMU does indeed have internal systems for determining frame
> times as defined in ui/console.c.
> The code checks for a variable called update_interval that it later
> uses for time calculation. This variable, however, isn't defined
> anywhere in ui/gtk.c and instead ui/console.c just sets it to
> GUI_REFRESH_INTERVAL_DEFAULT which is 30
>
> update_interval represents the number of milliseconds per display
> refresh, and by doing some math we get that 1000/30 = 33.33... Hz
>
> This creates the mentioned problem and what this patch does is that it
> checks for the display refresh rate reported by GTK itself (we can take
> this as a safe value) and just converts it back to a number of
> milliseconds per display refresh.
>
> Signed-off-by: Nikola Pavlica <pavlica.nikola@gmail.com>
Added to ui queue.
thanks,
Gerd
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-01-08 14:54 ` Philippe Mathieu-Daudé
2020-01-09 13:21 ` Gerd Hoffmann
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