drm/edid: Check both 60Hz and 59.94Hz when looking for a CEA mode
drm_match_cea_mode() should be able to match both the 60Hz version,
and the 59.94Hz version of modes.
We only store one pixel clock value per mode in edid_cea_modes, so the
other value must be calculated. Depending on the mode, edid_cea_modes
contains the pixel clock for either the 60Hz version or the 59.94Hz
version, so a bit of care is needed so that the calculation produces
the correct result.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=46800
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 9099eea..9e62bbe 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2330,13 +2330,34 @@
*/
u8 drm_match_cea_mode(const struct drm_display_mode *to_match)
{
- struct drm_display_mode *cea_mode;
u8 mode;
- for (mode = 0; mode < ARRAY_SIZE(edid_cea_modes); mode++) {
- cea_mode = (struct drm_display_mode *)&edid_cea_modes[mode];
+ if (!to_match->clock)
+ return 0;
- if (drm_mode_equal(to_match, cea_mode))
+ for (mode = 0; mode < ARRAY_SIZE(edid_cea_modes); mode++) {
+ const struct drm_display_mode *cea_mode = &edid_cea_modes[mode];
+ unsigned int clock1, clock2;
+
+ clock1 = clock2 = cea_mode->clock;
+
+ /* Check both 60Hz and 59.94Hz */
+ if (cea_mode->vrefresh % 6 == 0) {
+ /*
+ * edid_cea_modes contains the 59.94Hz
+ * variant for 240 and 480 line modes,
+ * and the 60Hz variant otherwise.
+ */
+ if (cea_mode->vdisplay == 240 ||
+ cea_mode->vdisplay == 480)
+ clock1 = clock1 * 1001 / 1000;
+ else
+ clock2 = DIV_ROUND_UP(clock2 * 1000, 1001);
+ }
+
+ if ((KHZ2PICOS(to_match->clock) == KHZ2PICOS(clock1) ||
+ KHZ2PICOS(to_match->clock) == KHZ2PICOS(clock2)) &&
+ drm_mode_equal_no_clocks(to_match, cea_mode))
return mode + 1;
}
return 0;