KMS/Wayland: Correct refresh rate units

On the wire, Wayland specifies the refresh rate in milliHz. Mutter sends
the refresh rate in Hz, which confuses clients, e.g. weston-info:
interface: 'wl_output', version: 2, name: 4
	mode:
		width: 2560 px, height: 1440 px, refresh: 0 Hz,
		flags: current preferred
interface: 'wl_output', version: 2, name: 5
	mode:
		width: 3200 px, height: 1800 px, refresh: 0 Hz,
		flags: current preferred

and xrandr:
XWAYLAND0 connected 2560x1440+3200+0 600mm x 340mm
   2560x1440@0.1Hz   0.05*+
XWAYLAND1 connected 3200x1800+0+0 290mm x 170mm
   3200x1800@0.1Hz   0.03*+

Export the refresh rate in the correct units. For improved precision,
perform the KMS intermediate calculations in milliHz as well, and
account for interlaced/doublescan modes.

This is also consistent with what GTK+ expects:
      timings->refresh_interval = 16667; /* default to 1/60th of a second */

      /* We pick a random output out of the outputs that the window touches
       * The rate here is in milli-hertz */
      int refresh_rate = _gdk_wayland_screen_get_output_refresh_rate (wayland_display->screen,
                                                                      impl->outputs->data);
      if (refresh_rate != 0)
        timings->refresh_interval = G_GINT64_CONSTANT(1000000000) / refresh_rate;

Where the 'refresh_rate' given is exactly what's come off the wire.
1000000000/60000 comes out as 16667, whereas divided by 60 is ...
substantially less.

https://bugzilla.gnome.org/show_bug.cgi?id=758653
This commit is contained in:
Daniel Stone 2015-11-25 12:56:18 +00:00 committed by Rui Matos
parent f3e1964362
commit c16a5ec1cf
2 changed files with 14 additions and 4 deletions

View File

@ -496,8 +496,18 @@ meta_monitor_manager_kms_read_current (MetaMonitorManager *manager)
meta_mode->name = g_strndup (mode->name, DRM_DISPLAY_MODE_LEN);
meta_mode->width = mode->hdisplay;
meta_mode->height = mode->vdisplay;
meta_mode->refresh_rate = (1000 * mode->clock /
((float)mode->htotal * mode->vtotal));
/* Calculate refresh rate in milliHz first for extra precision. */
meta_mode->refresh_rate = (mode->clock * 1000000LL) / mode->htotal;
meta_mode->refresh_rate += (mode->vtotal / 2);
meta_mode->refresh_rate /= mode->vtotal;
if (mode->flags & DRM_MODE_FLAG_INTERLACE)
meta_mode->refresh_rate *= 2;
if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
meta_mode->refresh_rate /= 2;
if (mode->vscan > 1)
meta_mode->refresh_rate /= mode->vscan;
meta_mode->refresh_rate /= 1000.0;
meta_mode->driver_private = g_slice_dup (drmModeModeInfo, mode);
meta_mode->driver_notify = (GDestroyNotify)meta_monitor_mode_destroy_notify;

View File

@ -99,7 +99,7 @@ bind_output (struct wl_client *client,
mode_flags,
(int)monitor_info->rect.width,
(int)monitor_info->rect.height,
(int)monitor_info->refresh_rate);
(int)(monitor_info->refresh_rate * 1000));
if (version >= WL_OUTPUT_SCALE_SINCE_VERSION)
wl_output_send_scale (resource, output->scale);
@ -160,7 +160,7 @@ wayland_output_update_for_output (MetaWaylandOutput *wayland_output,
mode_flags,
(int)monitor_info->rect.width,
(int)monitor_info->rect.height,
(int)monitor_info->refresh_rate);
(int)(monitor_info->refresh_rate * 1000));
}
/* It's very important that we change the output pointer here, as